Try entering different sets of numbers in the number pyramids. How does the total at the top change?
Do you notice anything about the solutions when you add and/or
subtract consecutive negative numbers?
Can you explain how this card trick works?
Delight your friends with this cunning trick! Can you explain how
Four bags contain a large number of 1s, 3s, 5s and 7s. Pick any ten
numbers from the bags above so that their total is 37.
Arrange the numbers 1 to 16 into a 4 by 4 array. Choose a number.
Cross out the numbers on the same row and column. Repeat this
process. Add up you four numbers. Why do they always add up to 34?
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?
How many solutions can you find to this sum? Each of the different letters stands for a different number.
For this challenge, you'll need to play Got It! Can you explain the strategy for winning this game with any target?
Can you find six numbers to go in the Daisy from which you can make all the numbers from 1 to a number bigger than 25?
Different combinations of the weights available allow you to make different totals. Which totals can you make?
This addition sum uses all ten digits 0, 1, 2...9 exactly once.
Find the sum and show that the one you give is the only
Is it possible to rearrange the numbers 1,2......12 around a clock
face in such a way that every two numbers in adjacent positions
differ by any of 3, 4 or 5 hours?
First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.
What are the missing numbers in the pyramids?
Replace each letter with a digit to make this addition correct.
In the following sum the letters A, B, C, D, E and F stand for six
distinct digits. Find all the ways of replacing the letters with
digits so that the arithmetic is correct.
Use the numbers in the box below to make the base of a top-heavy
pyramid whose top number is 200.
Choose any three by three square of dates on a calendar page.
Circle any number on the top row, put a line through the other
numbers that are in the same row and column as your circled number.
Repeat. . . .
If you take a three by three square on a 1-10 addition square and
multiply the diagonally opposite numbers together, what is the
difference between these products. Why?
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
The letters in the following addition sum represent the digits 1
... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
Find the values of the nine letters in the sum: FOOT + BALL = GAME
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
The idea of this game is to add or subtract the two numbers on the dice and cover the result on the grid, trying to get a line of three. Are there some numbers that are good to aim for?
This Sudoku, based on differences. Using the one clue number can you find the solution?
Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your oponent.
This is an adding game for two players.
This challenge extends the Plants investigation so now four or more children are involved.
This challenging activity involves finding different ways to distribute fifteen items among four sets, when the sets must include three, four, five and six items.
This article explains how to make your own magic square to mark a special occasion with the special date of your choice on the top line.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Find out about Magic Squares in this article written for students. Why are they magic?!
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
Make your own double-sided magic square. But can you complete both
sides once you've made the pieces?
Here is a chance to play a version of the classic Countdown Game.
Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
There are nasty versions of this dice game but we'll start with the nice ones...
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
If you have only four weights, where could you place them in order
to balance this equaliser?
Use your logical reasoning to work out how many cows and how many
sheep there are in each field.
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
Strike it Out game for an adult and child. Can you stop your partner from being able to go?
Choose a symbol to put into the number sentence.
Using 3 rods of integer lengths, none longer than 10 units and not
using any rod more than once, you can measure all the lengths in
whole units from 1 to 10 units. How many ways can you do this?
Got It game for an adult and child. How can you play so that you know you will always win?
Can you make a cycle of pairs that add to make a square number
using all the numbers in the box below, once and once only?