# Resources tagged with: Modular arithmetic

Filter by: Content type:
Age range:
Challenge level:

### There are 15 results

Broad Topics > Properties of Numbers > Modular arithmetic

### The Best Card Trick?

##### Age 11 to 16Challenge Level

Time for a little mathemagic! Choose any five cards from a pack and show four of them to your partner. How can they work out the fifth?

### Take Three from Five

##### Age 11 to 16Challenge Level

Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can they stop him?

### A One in Seven Chance

##### Age 11 to 14Challenge Level

What is the remainder when 2^{164}is divided by 7?

### Going Round in Circles

##### Age 11 to 14Challenge Level

Mathematicians are always looking for efficient methods for solving problems. How efficient can you be?

### It Must Be 2000

##### Age 7 to 11Challenge Level

Here are many ideas for you to investigate - all linked with the number 2000.

### Two Much

##### Age 11 to 14Challenge Level

Explain why the arithmetic sequence 1, 14, 27, 40, ... contains many terms of the form 222...2 where only the digit 2 appears.

### Where Can We Visit?

##### Age 11 to 14Challenge Level

Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?

### Elevenses

##### Age 11 to 14Challenge Level

How many pairs of numbers can you find that add up to a multiple of 11? Do you notice anything interesting about your results?

### What Numbers Can We Make?

##### Age 11 to 14Challenge Level

Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?

### What Numbers Can We Make Now?

##### Age 11 to 14Challenge Level

Imagine we have four bags containing numbers from a sequence. What numbers can we make now?

### How Much Can We Spend?

##### Age 11 to 14Challenge Level

A country has decided to have just two different coins, 3z and 5z coins. Which totals can be made? Is there a largest total that cannot be made? How do you know?

### Days and Dates

##### Age 11 to 14Challenge Level

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

### Differences

##### Age 11 to 14Challenge Level

Can you guarantee that, for any three numbers you choose, the product of their differences will always be an even number?

### Latin Squares

##### Age 11 to 18

A Latin square of order n is an array of n symbols in which each symbol occurs exactly once in each row and exactly once in each column.

### Round and Round and Round

##### Age 11 to 14Challenge Level

Where will the point stop after it has turned through 30 000 degrees? I took out my calculator and typed 30 000 ÷ 360. How did this help?