Reasoning, convincing and proving

article
Reasoning: identifying opportunities

In this article for primary teachers we consider in depth when we might reason which helps us understand what reasoning 'looks like'.
problem
School fair necklaces

Age

5 to 11

Challenge level

How many possible symmetrical necklaces can you find? How do you know you've found them all?
problem
Compare the cups

Age

5 to 7

Challenge level

You'll need a collection of cups for this activity.
problem
Count the crayons

Age

5 to 7

Challenge level

How could you estimate the number of pencils/pens in these pictures?
problem
Difference Sudoku

Age

14 to 16

Challenge level

Use the differences to find the solution to this Sudoku.
problem
Doubling fives

Age

5 to 7

Challenge level

This activity focuses on doubling multiples of five.
problem
Play to 37

Age

7 to 11

Challenge level

In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.
problem
Spot the fake

Age

14 to 16

Challenge level

One of N coins is slightly heavier than the others. How large can N be if the coin can be determined with only two weighings with a set of scales?
problem
Down and along

Age

11 to 14

Challenge level

Can you work out the values of J, M and C in this sum?
problem
Digital counter

Age

14 to 16

Challenge level

When the numbers from 1 to 1000 are written on a blackboard, which digit appears the most number of times?