Skill: List factor pairs

A factor pair is two positive whole numbers that multiply to make a given number. To list every factor pair, test numbers in order and record the matching factor.

Example: List the factor pairs of $24$.

1. Start with $1$:

$$1 \times 24 = 24$$

So, $(1,24)$ is a factor pair.

2. Try $2$:

$$2 \times 12 = 24$$

So, $(2,12)$ is a factor pair.

3. Try $3$:

$$3 \times 8 = 24$$

So, $(3,8)$ is a factor pair.

4. Try $4$:

$$4 \times 6 = 24$$

So, $(4,6)$ is a factor pair.

5. Try $5$. No positive whole number multiplied by $5$ equals $24$, so there is no pair beginning with $5$.

The complete list is

$$\boxed{(1,24),\ (2,12),\ (3,8),\ (4,6)}$$

Do not list $(24,1)$ or $(12,2)$ as new pairs. They use the same two factors in reverse order.