Problem 1
Three cards show the numbers 6, 9, and 12. One card is hidden. The total of all four cards is 38. What number is on the hidden card?
Answer: 11
- Add the visible cards: 6 + 9 + 12 = 27.
- Subtract from the total: 38 - 27 = 11.
- So the hidden card is 11.
How to explain it: Logic problems often become manageable when children list what is known and then find the missing part.
Problem 2
A pattern goes 6, 10, 14, 18, ... What is the next number, and what rule is being used?
Answer: 22, add 4 each time
- Compare the jumps: 10 - 6 = 4, 14 - 10 = 4, 18 - 14 = 4.
- The same rule repeats: add 4.
- So the next number is 18 + 4 = 22.
How to explain it: Encourage children to look at the change between numbers, not just the numbers themselves.
Problem 3
Sam, Priya, and Leo each chose a different fruit: apple, orange, or pear. Sam did not choose apple. Priya did not choose pear. Leo chose orange. Which fruit did each child choose?
Answer: Leo: orange, Sam: pear, Priya: apple
- Start with the clue we know for sure: Leo chose orange.
- That leaves apple and pear for Sam and Priya.
- Sam did not choose apple, so Sam chose pear.
- Therefore Priya chose apple.
How to explain it: These clue questions are easier when children cross out impossible choices instead of guessing.
Problem 4
A number has 2 digits. The tens digit is 5. The ones digit is 3 more than the tens digit. What is the number?
Answer: 58
- The tens digit is 5.
- The ones digit is 3 more, so it is 8.
- Put the digits together to make 58.
How to explain it: Children sometimes solve the clues but forget to rebuild the actual number from the digits.
Problem 5
Mia says a shape is a rectangle because it has 4 sides. Ben says that is not enough information. Who is correct?
Answer: Ben is correct
- Many shapes have 4 sides, not only rectangles.
- A rectangle also needs 4 right angles and opposite sides equal.
- So Ben is correct that 4 sides alone is not enough.
How to explain it: Logic in math is often about whether a clue proves enough, not just whether it sounds partly true.
Problem 6
Four children line up. Ava is not first. Ben is after Cara. Cara is before Ava. Ben is last. Who must be first?
Answer: Cara
- Ben is last, so he cannot be first.
- Cara is before Ava.
- Ava is not first.
- The only child who must be first is Cara.
How to explain it: Have your child test each clue one at a time instead of trying to hold the whole problem in their head.
Problem 7
A box contains red, blue, and green counters. There are more blue than red. There are fewer green than red. Which colour could have the greatest number?
Answer: Blue
- Blue is greater than red.
- Green is less than red.
- So blue must be the greatest.
How to explain it: Comparison logic becomes simpler when children rewrite each clue as an inequality in words or symbols.
Problem 8
A secret rule turns 3 into 11 and 5 into 19. If the same rule turns a number into “double it, then add 5,” what number turns into 27?
Answer: 11
- The rule is double the number, then add 5.
- Set up the puzzle: 2 × ? + 5 = 27.
- Subtract 5: 27 - 5 = 22.
- Divide by 2: 22 ÷ 2 = 11.
How to explain it: Reverse steps are a great logic habit. Undo addition before undoing doubling.
Problem 9
A square number chart is missing one entry. The row adds to 27. The visible numbers are 8, 6, and 9. What number is missing?
Answer: 4
- Add the visible numbers: 8 + 6 + 9 = 23.
- Subtract from the row total: 27 - 23 = 4.
- So the missing number is 4.
How to explain it: A lot of logic questions are really about finding a missing part once the structure is clear.
Problem 10
A clock shows a time between 4:00 and 5:00. The minute hand points to a number that is double the hour number. If the hour is 4, which number is the minute hand pointing to?
Answer: 8
- The hour number is 4.
- Double 4 to get 8.
- So the minute hand is pointing to 8.
How to explain it: Even small logic problems teach children to translate words like double and between into exact meaning.