Question

A library wants to buy a new computer that cost $989.99. So far, the library has collected $311.25 in donations.About how much more money does the library need to buy the computer?

Answer 1

Subtraction, 989.99 - 311.25 = $678.74 (answer)

Answer 2

$678.74 because you need $989.99 but you only have $311.25 so you need to subtract what you have and what you need( $989.999 $311.25 ) and you would get $678.74 now to check you have to add what you have and what you need($678.74 $311.25) and get $989.99