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### Number and algebra

### Geometry and measure

### Probability and statistics

### Working mathematically

### For younger learners

### Advanced mathematics

# Convince Me! - Upper Primary Students

### Beads and Bags

### Four-digit Targets

### Fifteen Cards

### Cuisenaire Spirals

### Money Bags

### Sealed Solution

### Stringy Quads

### Factor-multiple Chains

### Magic Vs

### A Bit of a Dicey Problem

### Chocolate

Links to the University of Cambridge website
Links to the NRICH website Home page

Nurturing young mathematicians: teacher webinars

30 April (Primary), 1 May (Secondary)

30 April (Primary), 1 May (Secondary)

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Here are some challenges that you can work on and then see if you can convince someone that your solutions are right! Have a go!

Age 5 to 11

Challenge Level

How could you put these three beads into bags? How many different ways can you do it? How could you record what you've done?

Age 7 to 11

Challenge Level

You have two sets of the digits 0-9. Can you arrange these in the five boxes to make four-digit numbers as close to the target numbers as possible?

Age 7 to 11

Challenge Level

Can you use the information to find out which cards I have used?

Age 7 to 11

Challenge Level

Can you make arrange Cuisenaire rods so that they make a 'spiral' with right angles at the corners?

Age 5 to 11

Challenge Level

Ram divided 15 pennies among four small bags. He could then pay any sum of money from 1p to 15p without opening any bag. How many pennies did Ram put in each bag?

Age 7 to 11

Challenge Level

Ten cards are put into five envelopes so that there are two cards in each envelope. The sum of the numbers inside it is written on each envelope. What numbers could be inside the envelopes?

Age 7 to 11

Challenge Level

This practical problem challenges you to make quadrilaterals with a loop of string. You'll need some friends to help!

Age 7 to 11

Challenge Level

Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?

Age 7 to 11

Challenge Level

Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?

Age 7 to 11

Challenge Level

When you throw two regular, six-faced dice you have more chance of getting one particular result than any other. What result would that be? Why is this?

Age 7 to 14

Challenge Level

There are three tables in a room with blocks of chocolate on each. Where would be the best place for each child in the class to sit if they came in one at a time?