### NRICH PROBLEM SOLVING KS2 NUMBER

What happens when you enter different numbers? Tasks for KS2 children which focus on working systematically. Mystery Matrix Age 7 to 11 Challenge Level: The tasks in this collection can be used to encourage children to convince others of their reasoning, by first convincing themselves, then a friend, then a ‘sceptic’. Buying a Balloon Age 7 to 11 Challenge Level: Can you find different ways of showing the same fraction? Watch the video to see how to fold a square of paper to create a flower.

Working Systematically at KS2. An investigation involving adding and subtracting sets of consecutive numbers. These upper primary tasks could all be tackled using a trial and improvement approach. Are these statements always true, sometimes true or never true? Balance of Halves Age 7 to 11 Challenge Level: Can you put the numbers in the V shape so that both ‘arms’ have the same total?

Use the lines on this figure to show how the square can be divided into 2 halves, 3 thirds, 6 sixths and 9 ninths. Can you find ways to make twenty-link chains from these smaller chains?

## Working Systematically at KS2

Fraction Lengths Age 7 to 11 Challenge Level: Every card he revealed had the same value as the splving he had just finished spelling. The tasks in this collection encourage lower primary children to conjecture and generalise. Can you fill in this table square? Are these statements always true, sometimes true or never true?

nricch Using the information given, can you replace the stars in the calculation with figures? How many ways can you find to do up all four buttons on my coat? Ordering Cards Age 5 to 11 Challenge Level: Can you see how these factor-multiple chains work? Find the product of the numbers on the routes from A to B. Remainders Age 7 to 14 Challenge Level: The tasks in this collection can be used to encourage children to convince others of their reasoning, by first convincing themselves, then a friend, then a ‘sceptic’.

# Working Systematically at KS2 :

Finding Fifteen Age 7 to 11 Challenge Level: What’s the smartest way to do it? Try adding fractions using A4 paper. John Mason talks about convincing yourself, convincing a friend and convincing a sceptic. Each light in this interactivity turns on according to a rule.

Reasoned Rounding nich Age 7 to 14 Challenge Level: You have two sets of the digits 0 — 9. How could you put these three beads into bags?

What’s in the Box? Always, Sometimes or Never?

Can nmber complete this calculation by filling in the missing numbers? Register for our mailing list. In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7.

Use these four dominoes to make a square that has the same number of dots on each side. And how do you know you’ve found them all?

## Problem-solving Skills

How many blocks would be needed to build an up-and-down staircase with 5 steps up and 5 steps down? Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether! Can you put the numbers 1 to 8 into the circles so that the four calculations are correct? How could you record what you’ve done? Consecutive Numbers Age 7 to 14 Challenge Level: Multiply Multiples 3 Age 7 to 11 Challenge Level: