nullifyMath puzzle & brain teaser
Combine all the numbers into a single one — and it has to be 0.
nullify is a math puzzle, number puzzle and brain teaser in one. Play it in your browser: start right away against the computer, or face others in a duel – also as a guest and without a download.
Unlike make24, the target is 0, and the numbers start at 1 and are all different – make24 can have a 0 and repeated numbers. Since adding, multiplying and dividing positive numbers never gives 0, every puzzle is built so that its numbers form two groups of equal value, as in the example. The operators are the same as in make24, and so are how many numbers each level has and how high they go – except that here you can’t multiply by 0 or divide 0, or it would swallow every other number.
Example: Level 3: turn 7, 12, 14, 28 and 38 into 0. Solution: 28 ÷ 14 = 2, 38 ÷ 2 = 19 and 7 + 12 = 19, so (7 + 12) − 38 ÷ (28 ÷ 14) = 0.
Levels: There are three numbers on level 1 and one more on each level up to level 5; levels 6 and 7 stay at seven. No number is below 1, and the upper limit is 14, 28, 42, 56, 70, 84 or 100, depending on the level.
In nullify you practice planning several steps ahead – for example, which numbers together come to the same value as the rest.
How to play
Everyone plays on their own board – all get the same puzzle.
Drag a number onto a number: they add up.
3onto5→8Put an operator on a number, then drag the second number onto it – the number with the operator comes first.
8−and3→8 − 3 =5√, x², n! … take effect at once.
√onto9→3The first to have only 0 left wins.
235→2 + 3 − 5 =0
The higher the level, the more and the bigger the numbers – seven at most.