There are 547 cookies in Mr Dobbs bakery A third grade class buys 169 cookies. Mr Dobbs wants to use mental math to figure out how many cookies he has left. First he subtracts 100 from 547 Then he subtracts 40 from 447. What should his next step be.

Question

Subtract 60 from 407
Subtract 20 from 407
Subtract 40 from 407
Subtract 100 from 407

Answer 1

Mr. Dobbs first subtracts 100 from 547, giving him 447 cookies left. Then he subtracts 40 from 447, which gives him 407 cookies remaining. To find out how many cookies he has left after selling 169 cookies in total, he needs to subtract the remaining amount of cookies sold.

To complete the calculation correctly, he should subtract 60 from 407 (because he still needs to account for 169 - 100 - 40 = 29 cookies).

So, the next correct step is: Subtract 60 from 407.