Reasoning, convincing and proving

Which of these triangular jigsaws are impossible to finish?

Which of these roads will satisfy a Munchkin builder?

Work in groups to try to create the best approximations to these physical quantities.

Can you make a square from these triangles?

Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?

You have been given nine weights, one of which is slightly heavier than the rest. Can you work out which weight is heavier in just two weighings of the balance?

You have twelve weights, one of which is different from the rest. Using just 3 weighings, can you identify which weight is the odd one out, and whether it is heavier or lighter than the rest?

These eleven shapes each stand for a different number. Can you use the number sentences to work out what they are?

How many bees could fly 1000 miles if they had 10 gallons of honey?

Take a look at the multiplication square. The first eleven triangle numbers have been identified. Can you see a pattern? Does the pattern continue?