At the school book fair, henry brings $10.00. he purchases a book for 8.50, plus a 6% sales tax. how much money in change will henry receive?

The book is $8.50, so all you need to do is multiply 8.5 * 0.06 (the 6% sales tax in decimal form)

8.5 * 0.06 = .51

Then add that to $8.50

$8.50 + $0.51 = $9.01

Then subtract from $10

$10 - $9.01 = $0.99

99 cents in change