Divide by Powers of 10 and Two-Digit Divisors

Question

Mr. Roberts had $9,512 in savings. He saved another $488. He then used all his money to buy 500 books. He sold the books for $35 each. How much did Mr. Roberts earn from selling each book?

Answer 1

9512 + 488 all divided by 500 = 20.  He spent 20 dollars per book.

 

If he sold each book for 35, and each book cost him 20, then he made $15 on each book.

Answer 2

Okay.

So he had $9512 and saved another $488 so,

9512 + 488 = 10000

 

He used that to buy 500 books so,

10,000 / 500 = $20 per book

He then sold the books for $35 each. If he paid $20 per book then $35 - $20 = $15

Mr. Roberts earned $15 per book by selling them