A number pattern follows a rule. In 4, 7, 10, 13, the rule is add 3. To find a missing number, work out the rule from the numbers next to each other.
Some patterns go down: 50, 44, 38, 32 has the rule subtract 6. Patterns in times tables have special features. Multiples of 4 are always even, and multiples of 5 always end in 0 or 5.
Worked example
What is the missing number? 6, 15, 24, ☐, 42
- Find the rule: 15 − 6 = 9 and 24 − 15 = 9, so add 9.
- 24 + 9 = 33. Check: 33 + 9 = 42.
Answer:33
Key words
- rule
- what you do each time to get the next number
- term
- one number in a pattern
- sequence
- numbers in a pattern
Practise this
New questions every time.
Common Core-referenced: 3.OA.D.9