KNS Puzzles offers the MathemaGrids puzzles in the following formats:
Puzzle A - 0 - 1 - 2 - 3 - random hints
Puzzle B - 0 - 1 - 2 - 3 - random hints
Puzzle C - 0 - 1 - 2 - 3 - random hints
Complete the grid using all of the digits 1 to 9. When completed all of the sums must be correct. The sums are solved strictly left to right, top to bottom.
The normal order of mathematical operations is ignored. For example 2 + 5 x 9 is calculated as (2 + 5) x 9 = 63. There are no ÷ 1 in the puzzle. There are no x 1 in the puzzle (although there might be 1 x).
At no point will any calculation go below zero, or fractional. What are the numbers for?
These are the sums that have to be satisfied once all of the digits 1 to 9 are entered.
This is the start of the puzzle.
There is only one way to make 28 = 4 x 7 (or 7 x 4). As there is no ÷ 1 in any puzzle, there is no way of making 7 with the first two digits. Therefore the last digit must be the 7.
There is only one way to make 22 = 5 + 8 + 9 (as the 7 has already been used).
We are still after the 4 (Step 2: 4 x 7 = 28) in Column 1, and 8 ÷ 2 is now the only way of doing this.
The only remaining way to make 24 is 2 x 3 x 4. So the missing digits in Row 2 are 3 and 4. Which means the remaining digits (1 and 6) must be in Row 3.
As there are no ÷ 1 in any puzzle, Row 3 must be 7 - 1 ÷ 6 = 1.
There is no way of reaching 42 in Column 3 if we use the 5, therefore Column 3 must be 9 x 4 + 6 = 42.
This cannot be 9, as we've already used it. Similarly the centre square cannot be 4. The puzzle now completes.
The completed puzzle.