Convert the rent first because the supplied multiplier is annual. $3,200 x 12 gives $38,400 annual gross rent. Then $38,400 x 9 gives an indicated value of $345,600.

Multiplying $3,200 by 9 gives $28,800, but that mixes monthly income with an annual multiplier. If a problem instead supplied an equivalent monthly multiplier of 108, the matching calculation would be $3,200 x 108 = $345,600.

Use the period the problem specifies; do not assume every book or exercise defines GRM on the same period. Keep gross rent in this calculation rather than replacing it with income after expenses. These figures are invented for practice, not a property estimate. The income-math worksheet compares multiplier and cap-rate calculations; BOE's capitalization lesson explains the underlying formulas.