Katrina is building a deck. She cuts 3 lengths of wood from a 72-inch board. The first length is $30\dfrac34$ inches. The second length is $12\dfrac14$ inches. And the third length is $16\dfrac14$ inches. How much of the original board remains after Katrina makes her cuts?

Question

justus · Answer

All you need to do is add them together then subtract 72

First step: Add the numbers 
30 and 3/4+12 and 1/4+ 16 and 1/4=30+3/4+12+1/4+16+1/4 =30+12+16+3/4+1/4+1/4=58+1+1/4=59+1/4=59 and 1/4

justus · Answer

Second step: Subtract from 72

72-59 and 1/4=72-(59+1/4)=72-59-1/4=71+1-59-1/4= 71-59+1-1/4= 71-59+4/4-1/4=12+3/4

justus · Answer

The answer is 12 and 3/4 inches