Build the idea
Explain your thinking with words, counters or a drawing.
- 27 + 15 = ____
- 28 + 15 = ____
- 29 + 15 = ____
- 25 + 15 = ____
All resources
Small puzzles. Shared discoveries.
Question a mistake, solve a mission together, or see a familiar skill somewhere new.
Reasoning sample · 7-9
A confident answer. A hidden mistake.
Read the character’s thinking, then explore a clearer explanation.
27 + 15 = 32. I added the ones and forgot their extra ten.
27 + 15 = 42
Explore the reasoning
7 + 5 = 12 ones. Exchange 10 ones for 1 ten, then add the tens: 27 + 15 = 42.
Challenge participation requires sign-in. Children practise through a parent-managed profile.
A small pack to repair the idea
Build the foundation, explain the mistake, then apply it in a new situation.
Repair the mistake
Explain your thinking with words, counters or a drawing.
- A character says 28 + 15 = 33. Correct the answer and explain the mistake.
- A character says 29 + 15 = 34. Correct the answer and explain the mistake.
- A character says 25 + 15 = 30. Correct the answer and explain the mistake.
- A character says 26 + 15 = 31. Correct the answer and explain the mistake.
Use it another way
Explain your thinking with words, counters or a drawing.
- A box has 29 counters. 15 are added. How many are there now?
- A box has 25 counters. 15 are added. How many are there now?
- A box has 26 counters. 15 are added. How many are there now?
- A box has 27 counters. 15 are added. How many are there now?
Original rule-based practice · Variation 42. Age bands are guidance. Review suitability before teaching. Public links contain generation settings only, never learner progress.