How to play Make 100
- A block from 10, 20, 30 up to 90 waits above the board. Tap a column to drop it there.
- If it lands next to a block that makes 100 with it, both blocks disappear: 10 and 90, 20 and 80, 30 and 70, 40 and 60, or 50 and 50.
- Blocks above a gap fall down and can make 100 with their new neighbours.
- The game ends when a column is full to the top.
Stuck? Press Hint to see a column where your block makes a bond. Every bond you make, the adder above the board eats it and grows one block longer.
Easy gives more blocks that fit somewhere, Tricky fewer.
For parents and teachers
Make 100 practises pairs of multiples of 10 that make 100. It is the bonds to 10 again, counted in tens: 3 tens and 7 tens make 10 tens. England’s national curriculum asks Year 2 children to derive and use related facts up to 100; in the US Common Core, adding and subtracting multiples of 10 starts in grade 1 (1.NBT.C).
A guide: ages 7 to 8, after Make 10.
The Block Adder games
- Make 5: Find two blocks that add up to 5, like 2 and 3.
- Make 10: Find two blocks that add up to 10, like 3 and 7.
- Make 20: Find two blocks that add up to 20, like 12 and 8.
- Make 100: Find two tens that add up to 100, like 30 and 70.
- Sums to 10: Drop each sum on its answer: 4 + 3 goes on a 7.
- Sums to 20: Drop each sum on its answer: 12 − 3 goes on a 9.
Questions
Why only tens?
Pairs of tens show the link with bonds to 10 most clearly. A child who knows 3 + 7 = 10 can see that 30 + 70 = 100.
What next after Make 100?
The Sums games mix adding and taking away: Sums to 10, then Sums to 20.
Is it safe for children?
Block Adder has no ads, no chat, no sign-up and no tracking. Nothing your child does is sent anywhere: the game in progress, the best scores and the statistics are kept only in this browser.
Does it work on a phone or tablet?
Yes. Tap a column to drop the block there. It fits a phone held upright, and it works with a mouse or the keyboard on a computer.
Keyboard
| 1 to 5 | Drop into that column |
|---|---|
| Left and right arrows | Move between columns |
| Enter or Space | Drop into the chosen column |
| H | Hint |