# Key Concepts

- Solve multiplication equations
- Solve division equations

## Solve multiplication equation:

To solve a multiplication equation, use the inverse operation of division. Divide both sides by the same non-zero number.

8 = ? × 4

A multiplication fact that matches this is 8 = 2 × 4

### Solve division equation

To solve a division equation, use the inverse operation of multiplication. Multiply both sides by the same number.

? = 80 ÷ 10

8 = 80 ÷ 10

### 4.8.1 Solve multiplication equations

To solve a multiplication equation, use the inverse operation of division. Divide both sides by the same non-zero number.

### Example1:

Sasha has some bags of fruits. Each bag has 6 fruits. Sasha has 18 fruits in all. How many bags of fruits does she have?

### Solution:

We can write an equation to represent the problem.

18 =? x 6

Some equation has symbols to represent unknowns.

The?** ** represents the number of bags of fruits Sasha has.

18 =? x 6

The multiplication fact that matches this is 18 = 3 x 6.

The value of? is 3.

So, ? = 3.

Sasha has 3 bags of fruits.

### Example2:

Rossi has some pack of sanitizer bottles. Each pack has 7 bottles. Rossi has 28 bottles in all. How many packs of sanitizers does she have?

### Solution:

We can write an equation to represent the problem.

28 =? x 7

Some equation has symbols to represent unknowns.

The?** ** represents the number of packs of bottles Rossi has.

28 =? x 7

The multiplication fact that matches this is 28 = 4 x 7.

The value of? is 4.

So, = 4.

Rossi has 4 packs of sanitizers.

## 4.8.2 Solve division equations

To solve a division equation, use the inverse operation of multiplication. Multiply both sides by the same number.

The pan balance shows 20 ÷ 5 = 4.

### Example1:

A gardener needs 40 gladioli bulbs. Bulbs are sold in packs of 8. How many packs should the gardener buy?

### Solution:

We can write an equation to represent the problem.

? = 40 ÷ 8

Some equation has symbols to represent unknowns.

The?** ** represents the number of packs of gladioli bulbs gardener buy.

? = 40 ÷ 8

The division fact that matches this is 5 = 40 ÷ 8

The value of ? is 5.

So,? = 5.

A gardener buy 5 packs of gladioli bulbs

### Example2:

Maria decides to run 7 miles for every day. How long will it take her to run 49 miles?

### Solution:

We can write an equation to represent the problem.

? = 49 ÷ 7

Some equation has symbols to represent unknowns.

The?** ** represents the number of days Maria run.

? = 49 ÷ 7

The division fact that matches this is 7 = 49 ÷ 7

The value of ? is 7.

So,? = 7.

7 days long will it take her to run 49 miles.

# Exercise:

- Find the value for? that makes the equation true.

a. 8 x ? = 24.

b. 3 x ? = 12.

c. 4 x ? = 32. - Find the value for? that makes the equation true.

a. ? ÷ 5 = 7

c. b. 40 ÷ 5 =?

d. ? = 36 ÷ 6 - Write and solve an equation that represents the problem.

A jewelry store has 56 rings to display. They arrange the rings in 8 even rows. Find how many rings are in each row? - Cadena baked 30 muffins and divided them equally into 5 tins. How many muffins did Cadena put in each tin?
- Fill in the missing number.

6. Find the product of the following.

a. 9 x 5 = ____________________

b. 5 x 5 = ____________________

c. 8 x 5 = ____________________

7. Find the quotient of the following.

a. 45 ÷ 5 = ____________________

b. 50 ÷ 5 = ____________________

c. 12 ÷ 4 = ____________________

8. Fill in the missing number.

a. 20 ÷ ______= 10

b. ______÷ 2 = 1

c. ______ ÷ 7 = 3

9. Balance the equation.

a. 16 ÷ 4 = 2 x ____.

b. 20 ÷ 2 = 5 x ____.

10. Balance the given division.

### Concept map:

### What have we learned:

- Understand multiplication and division equation.
- Understand how to solve multiplication equation
- Understand how to solve division equation.
- Understand how to write equation for word problems.
- Understand how to balance multiplication equation = division equation.