OPINION
PER CURIAM.I. INTRODUCTION
Alleging that her income had declined following her divorcee from George Haralovich, Barbara Shepherd asked the superior court to recalculate child support. Shepherd's income had declined in part because she had sold rent-producing property that she had been awarded in the divorcee. The superior court found that Shepherd's income was effectively the same as before. When Shepherd moved for reconsideration, the trial court considered that income Shepherd could realize from reinvesting net proceeds from the rental property sale would compensate for the small decline in her net income and denied reconsideration. Shepherd appeals the denial of her reconsideration motion and, among other things, argues that because she was not voluntarily underemployed, it was error to impute any income to her. We affirm the court's imputation of investment income because imputation does not require underemployment. But we remand the matter to the superior court to determine Shepherd's federal tax Hability and recalculate her adjusted annual income to account for that tax liability.
II. FACTS AND PROCEEDINGS
Barbara Shepherd and George Haralovich divorced in 2002 after a marriage of seventeen years. Shepherd was awarded primary physical custody of the parties' three children. The divorcee decree set Haralovich's base child support obligation at $1,654 per month. As part of the divorcee, Shepherd received the family home and also received a rental property estimated in 2002 to be worth $235,000. The rental property carried two mortgages totaling about $110,000. Shepherd sold the rental property for $265,000 in 2003.
In July 2008 the oldest child moved away from home. In December the court issued a new custody order for the two children still at home which set out a week on/week off schedule. In April 2004 the superior court issued a new child support order ending Har-alovieh's child support obligation for the oldest child and also changing the custody arrangement for the two remaining children. Child support was based on one child living week on/week off with both parents, while the other child resided primarily with Shepherd.
The April 2004 order also noted that Shepherd's January 2004 child support affidavit reflected less income than her 2002 affidavit, partly because she did not list any rental income in 2004. Shepherd's 2002 affidavit had listed her gross income as including $50,000 in wages, $21,288 in rental income, and $2,050 from other sources. The April 2004 order stated that the court would rely on Shepherd's 2002 affidavit in calculating income to compute child support unless Shepherd submitted supplemental information, including "her full 20083 federal tax return," that explained her decreased income. Based on Shepherd's 2002 affidavit, in April 2004 the superior court determined that Shepherd's net income was $51,639 after allowable deductions.
*645In response to the April 2004 order, Shepherd submitted an affidavit explaining that she had sold the rental property and declaring that "my income from rentals has gone from $21,288 to zero." She did not submit a tax return or equivalent documents.
In July 2004 the superior court issued another order regarding child support. The court used a January 2004 pay stub to estimate Shepherd's net income at $44,126; this was $7,513 less than the amount set out in the April order. The $44,126 figure did not include any income from rental property or any investment income from funds generated by the sale of the rental property. The superior court declared that "[wJhile Ms. Shepherd indicates that she sold her income-producing property, the court assumes that she could have continued to receive that income and/or that she re-invested those funds in such a way that is as or more financially advantageous as was previously the case." The superior court in its July order thus seemed to impute $7,518 in investment income to Shepherd. The court indicated that in calculating child support it would use an adjusted annual income figure of $51,639 for Shepherd. The superior court noted that Shepherd had still not submitted her 2003 federal tax return "and all attachments" or any "explanation under oath as to the amount and disposition of the proceeds of the income-producing property." The court announced that barring a request for reconsideration and submission of that information, it would issue a support order based on the prior calculation.
Shepherd then moved for reconsideration and submitted her affidavit attaching her 2002 and 2008 federal tax returns. Her 2008 tax return reflected a taxable wage income of $44,421 and a $95,893 capital gain from the sale of the rental property. She stated in her affidavit that the rental property "was not producing enough income to justify [her] holding it long-term." She also stated that the sale was made necessary by a poor financial position partially caused by Haralovich's failure to pay child support. She asserted that she did not re-invest any proceeds of the sale in a way that would provide her a regular income.
In September 2004 the superior court issued a third order, addressing Shepherd's reconsideration motion. Based on the financial information newly submitted by Shepherd with her reconsideration motion, the superior court calculated her adjusted net annual income at $50,780. The superior court noted that this figure was only $909 less than the net income of $51,639 it had used in the two prior orders. The superior court denied Shepherd's motion for reconsgid-eration; it reasoned that although her annual wages were $909 less than the court had previously assumed (excluding the $95,000 capital gain1), "it is reasonable to assume that at least some portion" of the proceeds of the sale of the rental property would be invested "in such a way as to net at least $909 per year." The superior court therefore concluded that "[the $51,639 net annual income" listed in Shepherd's 2002 Civil Rule 90.3 affidavit "appears to be at least that income that best reflects [Shepherd's] current income and/or income producing ability-fi
Shepherd appeals from the September order denying her reconsideration motion.
IIL STANDARD OF REVIEW
We review a trial court's denial of a motion for reconsideration for abuse of discretion.2 We review decisions to impute income for abuse of discretion.3 Whether a trial court has abused its discretion depends on whether "we are left with a definite and firm conviction, after reviewing the whole record, that the trial court erred in its ruling." *6464 But "[wlhether the trial court used the correct method of calculating child support is a matter of law, therefore we give no deference to the trial court's decision."5 We apply our "independent judgment when reviewing a lower court's interpretation of statutes and other related legal questions." 6
IV. DISCUSSION
A. The Superior Court Did Not Abuse Its Discretion by Considering the Income-Producing Capability of Funds from the Sale of the Rental Property.
Shepherd argues that the superior court erred by imputing income to her and that "income may only be imputed to 'a parent who voluntarily and unreasonably is unemployed or underemployed.'"7 Shepherd argues that "as a matter of law the trial court must make a determination of voluntary and unreasonable unemployment or underemployment" before imputing income.
We first observe that there is some question whether the superior court's final order denying reconsideration, issued in September, actually imputed any income to Shepherd. This uncertainty may stem from the three orders issued by the superior court. The April order imputed no income to Shepherd and was based on Shepherd's earlier statement that she had received approximately $21,000 in rental income. The July order may have imputed income of about $7,500 to Shepherd, but that order was superseded by the September order issued after Shepherd moved for reconsideration. Shepherd appeals the September order denying reconsideration.
In its April 2004 order, the superior court relied on Shepherd's 2002 child support affidavit and provided that child support would be based on her net income of $51,639. The superior court denied reconsideration in its September order because it found that Shepherd's financial information indicated her current income was $50,730. Therefore, the superior court's final order imputed, at most, $909 of investment income to Shepherd, the difference between $50,730 and the $51,639 referred to in the April 2004 order.
It is probable, however, that the superior court's consideration of potential investment income is not an imputation at all. If imputation is appropriate, a court typically finds the specific income to be imputed to the parent and uses this figure to calculate child support.8 The superior court here simply looked to the earning power of "at least some portion" of the proceeds from the rental property sale, and assumed they would "net at least $909 per year," in order to confirm that there was no significant difference between the income figure the court had used in its July order and the income figure described in Shepherd's reconsideration motion.
This was an appropriate way for the superior court to decide whether to grant Shepherd's motion for reconsideration. There was a difference of only $909 between the prior net income figure and the net income figure revealed in Shepherd's reconsideration affidavit. Shepherd's 2008 tax return listed the gross sales price of the rental property as $265,000. Given that the court had previously been informed that there were existing mortgages of approximately $110,000 on the property, it was reasonable to think that some net. proceeds from the sale of the property could have been safely reinvested and that the investment income would more than compensate for the relatively small difference in net income.
The superior court therefore did not abuse its discretion in concluding in September that the $51,639 net income figure the court used in the April and July orders to caleulate child *647support "reflects [her] current income and/or income producing ability." The court did not use the net of the sale proceeds to impute income. In deciding the reconsideration motion, the court instead appears to have relied on the net proceeds only to conduct a reality check to determine whether there was a significant difference between Shepherd's income as previously determined in April and her income as represented in her motion for reconsideration, and thus to determine whether Shepherd's Civil Rule 77 reconsideration motion should be granted.
In any event, it would not have been an abuse of discretion to impute some investment income to Shepherd from the sale proceeds of the rental property. Her primary argument, that investment income ean "only be imputed to a parent who voluntarily and unreasonably is unemployed or underemployed," misreads Alaska Civil Rule 90.3.
Alaska Civil Rule 90.8(a)(4) states:
The court may calculate child support based on a determination of the potential income of a parent who voluntarily and unreasonably is unemployed or underemployed. ... Potential income will be based upon the parent's work history, qualifications, and job opportunities. The court also may impute potential income for non-income or low income producing assets.
(Emphasis added.) "Also" indicates that imputing income from underproducing assets differs from imputation based on underemployment. In effect, Rule 90.8(a)(4) provides that a court may impute employment income when there is unreasonable underemployment and may impute investment income when there is a non-income or low-income producing asset. The rule does not expressly or implicitly condition imputation of investment income on unemployment or underemployment.
Shepherd cites several cases discussing the unemployment or underemployment of parents 9 and asserts that "[the unifying theme in these opinions is ... that income may only be imputed to 'a parent who voluntarily and unreasonably is unemployed or underemployed.'"10 These cases are not on point because they only discuss employment income and do not discuss underperforming assets. Shepherd cites nothing to suggest that the "voluntarily and unreasonably ... underemployed" finding that Rule 90.3 requires before imputing employment income is also required if income is to be imputed from underperforming assets.
Moreover, our decisions indicate that it is not necessary to find underemployment before imputing asset income. In Laybourn v. Powell, we held that "the superior court properly imputed income to Laybourn based on his efforts to disguise actual earnings and conceal assets," even though there was no finding that he was underemployed or unemployed.11 We noted that underreporting income or hiding assets is "functionally equivalent to voluntary underemployment." 12 We did not discuss whether a finding of deliberate underemployment is necessary for imputation of income from assets (and presumably the parties had not argued this), but we had no difficulty affirming an imputation of income to someone who was fully employed but hiding assets.
In Ogard v. Ogard, we noted that "where an obligor parent has reduced his or her income by liquidating income-producing assets and applying the proceeds to the mortgage on his or her dwelling," a trial court *648might have good cause to impute earnings.13 The American Law Institute (ALT) recommends imputation of asset income without regard to whether the parent is underemployed. The Institute's Principles of the Law of Family Dissolution: Analysis and Recommendations states that "[iln calculating a parent's income, the court may ... (b) impute an ordinary rate of return to an asset that yields less than an ordinary rate of return." 14 The ALI further explains that a "court should impute an ordinary rate of return" on a stock portfolio producing little or no income even for someone who is employed and "earns a substantial salary." 15
Given Rule 90.8(a)(d)'s statement that "tlhe court also may impute potential income for ... low income producing assets" and our precedents, it would not have been error to impute investment income to Shepherd without first finding deliberate underemployment. i
Shepherd also briefly argues that investment income should not be imputed because she did not unreasonably and voluntarily forgo income-producing assets. She contends that selling the rental property was reasonable and that "given her then-extant economic cireumstances, it would be difficult to conclude that selling the property was actually voluntary." The voluntary and unreasonable requirements set out in Rule 90.3 for imputation expressly apply only to unemployment and underemployment.16 Thus, in Ogard, we noted that the trial court could impute earnings if a parent sold income-producing assets in order to reduce mortgage payments.17 Such a reinvestment would not be unreasonable, but selling one investment to offset Habilities would presumably improve the parent's financial situation, and it is not obvious why it would be reasonable to decrease that parent's share of child support based on the "loss" of the asset. Also, the issue is not whether it was unreasonable for Shepherd to sell the property. It is whether, having sold the property, Shepherd could fail to use any of the net sales proceeds to generate income. Shepherd has not squarely disputed that issue. She did not demonstrate below that the sales proceeds were exhausted or that the superior court erred in stating that "it is reasonable to assume that at least some portion of this money will be invested in such a way as to net at least $909 per year." Given the evidence before the court on reconsideration, the court could reason that it would have been unreasonable to use none of the sales proceeds to generate some nominal replacement income.
Shepherd argues in the alternative that even if the superior court did not err by imputing some investment income, it erred in determining the amount of Shepherd's adjusted income for child support purposes. Shepherd asserts that the net rental income of approximately $21,000 would have been reduced by the cost of a "handyperson" because she could not have performed building maintenancé herself. She also asserts that the $21,000 figure she listed for 2002 was wrong because it was for "all" of the parties' rental properties, not just the rental property awarded to her. Hence "[tlo impute future income from property Ms. Shepherd did not then own is simply unsupported by case law, this record, or common sense." Third, she asserts that the rental income should have been averaged over a two- or three-year period. These three contentions are all based on her assumption that the superior court imputed rental income to Shepherd. But the court did not impute rental income. At most, the superior court imputed income from some portion of the net sale proceeds.
Finally, Shepherd argues that the court erred in considering the proceeds from the sale of the rental property because they re*649sulted from a one-time sale and were not regular income. Rule 90.83, Commentary III(A) suggests treating capital gains as income only if they "represent a regular source of income." The superior court did not treat the one-time capital gain as income; the court only considered the nét sale proceeds insofar as they could have been reinvested to provide a source of regular income. The commentary to Rule 90.3 III(A) states that "one-time gifts and inheritances should not be considered as income, but interest from the principal amount should be considered as income." By implication, there is nothing wrong with treating investment income from a one-time capital gain as income.
B. It Was Error To Calculate Child Support Based on the Assumption that Shepherd Would Have No Federal Income Tax Liability.
In calculating allowable deductions for child support determination purposes, the superior court assumed that Shepherd would pay no federal income taxes on her income. The superior court noted in its September order:
In 2002, Ms. Shepherd owed no federal income taxes. In 2003, she owed $14,335 in federal income taxes. However, these high taxes are tied to her sale of the rental property and receipt of $95,893 in capital gains.... Since her actual tax liability for 2002 was zero, that number (zero) appears to most closely approximate actual projected federal income tax lability.
A threshold question is whether the correctness of the trial court's assumption in calculating child support that there would be no federal income tax Hability has been raised and argued sufficiently so as to be properly before us on appeal. In her brief, Shepherd raises the question whether the record supports the trial court's calculation of imputed income and points out that she sought reconsideration of the trial court's decision, submitting both her 2002 and 2008 income tax returns and attachments from both returns. And in her statement of the case, Shepherd contends that she explained to the trial court "that she did not have tax liability for 2002 because that year she incurred significant legal expenses in relation to properties at issue in the divorcee. She indicated that the legal expenses were deductible for federal tax purposes in tax year 2002 only. No one challenged this valid deduction." Shepherd further maintains in her brief that she informed the trial court that she "used the proceeds from the sale [of the rental property] to pay $14,835 in federal taxes for 2008." Shepherd then points out that "[the trial court failed to mention or discuss why Ms. Shepherd did not incur income tax liability for 2002; the one-time expense of legal services related to the preservation of her income-producing property. Instead, it used the aberration of property sale-related taxes in 2003 to justify no tax liability or deductions in 2004."
Shepherd further maintains in her brief that "[t]he trial court also rejected the use of standard deductions since Ms. Shepherd itemizes deductions and has three exemptions for income tax purposes. The court believed that since Ms. Shepherd's tax liability for 2002 was zero, that amount should be used as it 'appears to most closely approximate actual projected federal income liability.'" "Based on this flawed analysis," Shepherd complains, "the trial court concluded that 'the $51,639 net annual income Ms. Shepherd represented as adjusted net income in her 2002 ARCP 90.8 affidavit appears to be at least that income that best reflects current income and/or income producing ability' and thus denied Ms. Shepherd's motion for reconsideration." Although these arguments are made under the heading of "statement of the case," rather than in the argument section of Shepherd's brief, we conclude that they are adequate to raise the claim on appeal.
But Shepherd also argues two major legal points in the argument section of her brief: (1) that the trial court erred in imputing rental income, and (2) that, even if income could be imputed, the record failed to support the court's caleulation of the amount of her imputed income. In addressing the see-ond point, her alternative claim of computational error, Shepherd specifically argues:
[Slhould the court be otherwise inclined to impute non-existent net rental income, it *650should average that income. As demonstrated by Ms. Shepherd's 2002 and 2008 federal tax returns, rental income from the Grant Street property varied from $8,904 (in 2002) to 0 in 2003, for a two-year annual average of $4,452. Since the property was sold in 2008, though, Ms. Shepherd will receive no rental proceeds from it in 2004, or hereafter and a three year average would yield an average annual rental income of $2,968.
This argument squarely addresses the computational flaw that Shepherd describes in her statement of facts: the superior court's failure to recognize that Shepherd's 2002 zero federal tax liability was a one-time event. Shepard's argument for averaging hinges on the validity of her claim that the 2002 tax deduction was non-recurring. While Shepherd's argument does not draw this connection explicitly, the point is implicit, and her minimal treatment of it seems unsurprising given that the reason for the zero tax liability in 2002 has apparently never been questioned.
In responding to a question from this court at oral argument, Shepherd maintained that the superior court's September order was erroneous because the court assumed Shepherd's normal federal income tax liability was zero. For all of these reasons, we conclude that the issue of Shepherd's tax Hability is properly before us, and we therefore turn to the merits. Under Civil Rule 90.8(a)(1)(A)G), federal income tax is to be deducted from a parent's gross income in order to determine the parent's adjusted annual income. We have previously directed that federal income tax liability should be deducted from imputed income.18 Therefore, we remand this case to the trial court to determine the amount that should be deducted from Shepherd's income. On remand, the trial court may take into account the actual tax liability of Shepherd as reflected in her tax returns.
v. CONCLUSION
For the reasons stated above, the superior court's imputation of investment income is AFFIRMED but the case is REMANDED so that the trial court may determine the amount of Shepherd's federal income tax liability and recalculate Shepherd's adjusted annual income to account for that tax liability.
EASTAUGH, Justice, with whom CARPENETI, Justice, joins, dissenting in part.
. Alaska Civil Rule 90.3, Commentary III A(16) suggests capital gains should be treated as income only "to the extent they represent a regular source of income."
. Neal & Co., Inc. v. Ass'n of Vill. Council Presidents Reg'l Hous. Auth., 895 P.2d 497, 506 (Alaska 1995).
. O'Connell v. Christenson, 75 P.3d 1037, 1039 (Alaska 2003) (citing Rhodes v. Rhodes, 754 P.2d 1333, 1335 (Alaska 1988).
. Peter Pan Seafoods, Inc. v. Stepanoff, 650 P.2d 375, 378-79 (Alaska 1982).
. Turinsky v. Long, 910 P.2d 590, 594 n. 10 (Alaska 1996) (citing Charlesworth v. State, Child Support Enforcement Div., 779 P.2d 792, 793 (Alaska 1989)).
. Paxton v. Gavlak, 100 P.3d 7, 10 (Alaska 2004).
. Quoting Alaska Civil Rule 90.3, Commentary III(C).
. See, e.g., O'Connell, 75 P.3d at 1038 (explaining that superior court imputed income of $43,550.13 to O'Connell and then calculated his support obligation based on this amount).
. Shepherd's brief cites: Nunley v. State, Dep't of Revenue, Child Support Enforcement Div., 99 P.3d 7 (Alaska 2004); Olmstead v. Ziegler, 42 P.3d 1102 (Alaska 2002); Robinson v. Robinson, 961 P.2d 1000 (Alaska 1998); Vokacek v. Vokacek, 933 P.2d 544 (Alaska 1997); Kowalski v. Kowalski, 806 P.2d 1368 (Alaska 1991); and Pattee v. Pattee, 744 P.2d 658 (Alaska 1987). Pattee is the only one of these cases to mention sale of assets, but Pattee did not involve imputation of asset income, and it was decided under the framework existing before Rule 90.3, which was adopted by Supreme Court Order No. 833 (April 30, 1987), and became effective in August 1987. See Pattee, 744 P.2d at 662.
. Quoting Alaska Civil Rule 90.3, Commentary III(C).
. Laybourn v. Powell, 55 P.3d 745, 746 (Alaska 2002).
. Id. at 747.
. Ogard v. Ogard, 808 P.2d 815, 819 n. 6 (Alaska 1991).
. American Law Institute, Princmpess or tur Law or Famiy Dissorurion: Anatysts amp Recommenpations § 3.14(4) (2002).
. Id. at § 3.14 cmt. d.
. 'The court may calculate child support based on a determination of the potential income of a parent who voluntarily and unreasonably is unemployed or underemployed." Alaska Civil Rule 90.3(a)(4).
. Ogard, 808 P.2d at 819 n. 6.
. Rodvik v. Rodvik, 151 P.3d 338, 351 (Alaska 2006).