What Comes Next? #396

Pattern puzzle 396 card

Challenge type: What Comes Next?  ·  Difficulty: ★★★★★ Super tricky

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

Pattern: 1, 3, 6, 10, 15, 21, then a question mark. Choices: A: 30; B: 56; C: 31; D: 28.
What comes next: A, B, C or D?

The pattern in words: 1, 3, 6, 10, 15, 21, and then… what?

Your choices

  • A: 30
  • B: 56
  • C: 31
  • D: 28
Need a hint?

Look at the gaps: they go up by one each time.

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.