Challenge type: What Comes Next? · Difficulty: ★★★★☆ Tricky
Computers are brilliant at spotting patterns, and so are you. Look carefully at this row.
The pattern in words: 39, 36, 33, 30, 27, 24, and then… what?
Your choices
- A: 21
- B: 26
- C: 22
- D: 31
Need a hint?
The numbers are getting smaller. By how much?
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.