Owl's Riddle
- Explorers
- Levels 1 and 2
- Matchstick puzzle
Another wonky sum! 1 + 0 = 7. Move one matchstick to fix it.
Move one matchstick so the sum is true.
This one comes back on . You can solve it then, signed in.
Last set on . The answer stays inside Kiwimath, and here is why.
What the board shows
- As laid out, the sum reads 1 + 0 = 7, which is not true.
- There are 15 matchsticks on the table, and the same 15 must still be there after the move.
- You may move one stick, and only once.
How do matchstick puzzles work?
The sum is built from matchsticks, with each figure made the way a calculator shows it: seven places for a stick, like an 8 with every stick in place. The plus sign is two sticks, the minus sign one, and the equals sign two.
A move means picking up one stick and putting it down somewhere else. It can go back into the same figure, into a different figure, or into a sign. Nothing can be thrown away or added from outside.
After the move every figure has to be a proper digit and the sum has to be true. A child who finds a true sum can check the move by counting the sticks: there should be exactly as many as at the start.
What it trains: Number sense, careful checking and seeing digits as shapes.
Puzzles like this are part of olympiad preparation from the first classes. See the plan for Class 1 or Class 3.
What to ask while your child works
Questions like these keep a child thinking without giving anything away. They work for every puzzle of this kind.
- Can you read the sum aloud and say why it is not true?
- How many sticks does each figure use?
- After your move, did the number of sticks stay the same?
Warm up with one like Owl's Riddle
This warm-up is not the puzzle above, and its answer is below. It is a different puzzle of the same kind, made for this page, so your child can practise before Owl's Riddle comes back.
Move one matchstick so the sum is true.
See the warm-up answer
The sum becomes 8 + 1 = 9.
- Eight take away one is seven, and no single stick turns either 8 into a 7. So look at the sign.
- Take the bottom-left stick from the 8 after the equals sign. It becomes a 9.
- Lay that stick upright across the minus sign, which turns it into a plus.
- Now it reads 8 + 1 = 9.
Questions parents ask about Owl's Riddle
When can my child solve Owl's Riddle?
Owl's Riddle is due back as the Explorers puzzle of the week on Saturday 12 December 2026, opening at 6 PM India time. Your child can solve it then, signed in, with hints that open one at a time.
Who is Owl's Riddle for?
It is an Explorers puzzle, for Levels 1 and 2, roughly Class 1 to 4. A younger child can try it with a grown-up reading the story aloud; the thinking matters more than the reading.