What Comes Next? #230

Pattern puzzle 230 card

Challenge type: What Comes Next?  ·  Difficulty: ★★★☆☆ Medium

A pattern is a rule that repeats. Find the rule, and you can tell what comes next. Beep boop!

Pattern: 12, 15, 18, 21, 24, 27, then a question mark. Choices: A: 20; B: 32; C: 30; D: 28.
What comes next: A, B, C or D?

The pattern in words: 12, 15, 18, 21, 24, 27, and then… what?

Your choices

  • A: 20
  • B: 32
  • C: 30
  • D: 28
Need a hint?

Find the difference between two numbers next to each other.

Did you know? When coders spot a pattern, they can write a loop: a few lines of code that repeat the rule as many times as they like. The answer page shows this pattern as real Python code!

For teachers and grown-ups

Skills practised: Pattern recognition, abstraction, and predicting the next step of a rule.

The big idea: Spotting a pattern lets a programmer replace lots of repeated steps with one short loop.

Questions to ask:

  • What is the rule, in your own words?
  • How many items repeat before the pattern starts again?
  • What would the 20th item be? How could you work it out without drawing them all?

Take it further: Children invent their own pattern with a hidden rule and challenge a partner to find it.