Lesson 9: Practice Problems

Problem 1

Write each subtraction equation as an addition equation.

$a - 9 = 6$
$p - 20 = - 30$
$z - (- 12) = 15$
$x - (- 7) = - 10$

Problem 2

Find each difference. If you get stuck, consider drawing a number line diagram.

$9 - 4$
$4 - 9$
$9 - (- 4)$
$- 9 - (- 4)$
$- 9 - 4$
$4 - (- 9)$
$- 4 - (- 9)$
$- 4 - 9$

Problem 3

Find the solution to each equation mentally.

$30 + a = 40$
$500 + b = 200$
$- 1 + c = - 2$
$d + 3, 567 = 0$

Problem 4 From Unit 6 Lesson 7

A restaurant bill is $59 and you pay $72. What percentage gratuity did you pay?

Problem 5

One kilogram is 2.2 pounds. Complete the tables. What is the interpretation of the constant of proportionality in each case?

pounds
kilograms
$2.2$
$1$
$11$
$5.5$
$1$
kilogram per pound.
kilograms
pounds
$1$
$2.2$
$7$
$30$
$0.5$
pounds per kilogram.