Skill: Describe pattern rules

A pattern rule tells how to get from one term to the next. It is more than just naming the next number.

Example:
Find the missing terms and describe the rule.

$$4,\ 8,\ 12,\ 16,\ \square,\ \square$$

Step 1: Compare neighboring terms.

• $4$ to $8$: add $4$
• $8$ to $12$: add $4$
• $12$ to $16$: add $4$

The same change happens each time.

Step 2: State the rule.

The rule is: add $4$ to get the next term.

Step 3: Use the rule to find the missing terms.

• $16+4=20$
• $20+4=24$

So the completed pattern is

$$4,\ 8,\ 12,\ 16,\ 20,\ 24$$

The pattern rule is add $4$ each time, and the next term after $24$ would be $28$.