When subtracting 2.9 from a certain number, the result is 64.24, as seen below. what number should go in the box to complete the subtraction problem? the decimal 2.9 is subtracted from an unknown whole number to get 64.24. the unknown whole number has 6 in the tens place, an unknown number in the ones place, 1 in the tenths place, and 4 in the hundredths place.