Activities for Families

Start with a 4 by 4 grid of numbers with a target sum. The challenge is to find entries to remove so that the sum of the remaining numbers in every row and column is the target. An alternative version uses individual target sums for each row and column.

Make these puzzles by putting in pairs or triples of numbers that sum to the target sum. Then fill in the remaining spaces with decoy numbers. You can make these trickier by having alternative pairs or triples of numbers that partially work. If your child is enjoying these, but finding them too easy, you can always make larger ones that are 4 by 5, 5 by 5, or even larger.

Red stars have been added here to show which entries would be removed to make the puzzles work.

Here are two puzzles using individual target sums for the rows and columns.

Puzzles are meant to be challenging and to take time, so please don’t ruin the fun by telling your child how to do them. These puzzles are chosen so that you can create them easily and then have fun solving them together.

If your child gets stuck on a puzzle, you have several options. You can, of course, give very small hints, if you can think of things that won’t give away the puzzle. You can suggest looking at smaller or simpler versions of the puzzle. Encourage your child to be bold in their ideas, even if sometimes they lead to dead ends. We all learn a lot from our mistakes and dead ends! Let your child know that it is perfectly okay not to solve a puzzle on the first (or second or third) try, and that useful ideas may occur to them if they leave the puzzle alone for a day or two.

These puzzles are meant to be fun and to teach problem solving. One of the greatest mathematical pleasures is that AHA moment, after many false starts and much wrestling with a problem, when the answer is finally discovered – be sure to let your child experience that feeling of discovery as many times as you can!