1

Drag the numbers onto the grid so that no number appears more than once in any row or column. Create the correct calculations as shown in the red rectangles.

Well done. You have solved this puzzle. Claim a trophy using the button below then come back and try one of the other levels.

Your answer is not correct.

3+

7+

5+

1−

1−

5+

7+

3+

1

1

1

1

2

2

2

2

3

3

3

3

4

4

4

4

This is Numskull level 1. You can also try:

Level 2
Level 3
Level 4
Level 5

The objective of this puzzle is to drag the numbers in yellow circles on to the four by four grid so that each of the different numbers appears once, and only once in each row and column. In each red rectangle there is room for two numbers. In the top left corner is a clue in the form of a number followed by a mathematical operation. This clue should help you work out which two numbers should be placed in that rectangle. For example if the clue is '6x' you know that the two numbers should multiply together to give a product of six. Similarly '3-' is the clue for two numbers with a difference of three.

Transum's Numskull is based on the idea of a Latin square inspired by mathematical papers written by Euler (1707 – 1783). The addition of the red rectangle totals is similar to popular Japanese puzzles which appear in newspapers around the world.

This is an ideal activity for those wishing to develop their numeracy skills and logical thinking. There are five different levels and each puzzle is created from random numbers every time the page is loaded in a browser so you are very unlikely to get the same puzzle twice.

Sign up for a Transum subscription to see the answers to all of the Numbskull puzzles.

If you like this puzzle you may want to try Suko Sujiko.

Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for those learning Mathematics anywhere in the world. Click here to enter your comments.