# Lesson 5

Representing Subtraction

The practice problem answers are available at one of our IM Certified Partners

### Problem 1

Write each subtraction equation as an addition equation.

1. $$a-9 = 6$$
2. $$p-20=\text-30$$
3. $$z-(\text-12)=15$$
4. $$x-(\text-7)=\text-10$$

### Problem 2

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

1. $$9 - 4$$

2. $$4 - 9$$

3. $$9 - (\text-4)$$

4. $$\text-9 - (\text-4)$$

5. $$\text-9 - 4$$

6. $$4 - (\text-9)$$

7. $$\text-4 - (\text-9)$$

8. $$\text-4 - 9$$

### Problem 3

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

(From Grade7, Unit 4, Lesson 10.)

### Problem 4

Find the solution to each equation mentally.

1. $$30+a=40$$
2. $$500+b=200$$
3. $$\text-1+c=\text-2$$
4. $$d+3,\!567=0$$

### 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

(From Grade7, Unit 2, Lesson 3.)