BrightKidz Library
Subjects
A jigsaw with one piece lifted out Six jigsaw pieces joined into a block, their knobbly cut lines showing. The piece from the top middle has been taken out, leaving a dark hole with three tabs poking into it. That same piece floats to the right, tilted over, and a dashed arrow curves back from it towards the gap it came from.

Cracking Fun Brain Teasers and Puzzles

About 6 minutes

Puzzles come in kinds, and each kind is beaten a different way. A riddle wants you to notice a word means two things. A logic puzzle wants you to rule things out patiently. Knowing which one you are holding is most of the battle.

Riddles: The Word Is the Trap

A riddle describes something in a way that is completely true and completely misleading at the same time. The trick is nearly always a word doing a second job.

What has an eye, but cannot see?

The word doing the work is eye. You pictured the thing on a face; a needle's eye is the hole you thread cotton through. Nothing in the riddle was untrue — your own assumption was the obstacle.

Once you know to look for the double meaning, riddles get much easier. What has a face and two hands but no arms? You are already checking "face" for a second meaning, and there is a clock on the wall.

Logic Puzzles: Rule Things Out

Logic puzzles give you clues that mostly say what is not true. That feels unhelpful and is the opposite.

The puzzle. Alex, Ben and Carol each like a different fruit: apple, banana or cherry.

  1. Write the three names down with the three fruits beside each, so you can cross options off as you rule them out.
  2. Take the clue that says something is true. Ben likes red fruit, and the only red one here is the cherry. Ben has the cherry.
  3. Remove what is now taken. Nobody else can have the cherry, so cross it off Alex and Carol.
  4. Apply the negative clues. Alex has no apples, and his cherry is gone, so Alex has the banana.
  5. Whatever is left belongs to whoever is left. Carol has the apple — which also fits her clue, since it is not a banana.

The answer: Alex has the banana, Ben the cherry, Carol the apple.

Step 2 is the move to remember. One clue that says is beats three that say is not, so always look for it first.

Number Puzzles: The Magic Square

Here is one to do on paper. Put the numbers 1 to 9 in this grid, using each number once, so that every row, every column and both long diagonals add up to 15.

An empty three by three grid for the magic square Nine empty squares in three rows of three. The numbers 1 to 9 each go in one square so that every row, every column and both diagonals add up to fifteen.
The dotted lines are the two diagonals. They have to add up to 15 as well.

Hint: put the 5 in the middle.

Here is why that is a good guess. The numbers 1 to 9 add up to 45, and the three rows each have to make 15 — which checks out, because 3 lots of 15 is 45. The average of all nine numbers is 45 ÷ 9 = 5, and the center square is the one square that sits on four different lines at once. The most balanced number belongs in the most connected place.

If you get stuck, try the corners next. The 5 in the center is the pivot everything else balances around.

Why Bother

Puzzles are practice at being stuck. That sounds like a small thing and it is not: most real problems feel impossible for a while before they come apart, and the useful skill is staying calm in the gap rather than being fast.

Every puzzle you finish makes the next one's stuck part feel more familiar.