Resources tagged with: Addition & subtraction

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There are 227 results

Broad Topics > Calculations and Numerical Methods > Addition & subtraction

Seven Square Numbers

Age 7 to 11
Challenge Level

Add the sum of the squares of four numbers between 10 and 20 to the sum of the squares of three numbers less than 6 to make the square of another, larger, number.

One Wasn't Square

Age 7 to 11
Challenge Level

Mrs Morgan, the class's teacher, pinned numbers onto the backs of three children. Use the information to find out what the three numbers were.

Pouring the Punch Drink

Age 7 to 11
Challenge Level

There are 4 jugs which hold 9 litres, 7 litres, 4 litres and 2 litres. Find a way to pour 9 litres of drink from one jug to another until you are left with exactly 3 litres in three of the jugs.

Penta Post

Age 7 to 11
Challenge Level

Here are the prices for 1st and 2nd class mail within the UK. You have an unlimited number of each of these stamps. Which stamps would you need to post a parcel weighing 825g?

The Deca Tree

Age 7 to 11
Challenge Level

Find out what a Deca Tree is and then work out how many leaves there will be after the woodcutter has cut off a trunk, a branch, a twig and a leaf.

Clock Face

Age 7 to 11
Challenge Level

Where can you draw a line on a clock face so that the numbers on both sides have the same total?

The Pied Piper of Hamelin

Age 7 to 11
Challenge Level

This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!

It Was 2010!

Age 5 to 11
Challenge Level

If the answer's 2010, what could the question be?

Napier's Bones

Age 7 to 11
Challenge Level

The Scot, John Napier, invented these strips about 400 years ago to help calculate multiplication and division. Can you work out how to use Napier's bones to find the answer to these multiplications?

Dividing a Cake

Age 7 to 11
Challenge Level

Annie cut this numbered cake into 3 pieces with 3 cuts so that the numbers on each piece added to the same total. Where were the cuts and what fraction of the whole cake was each piece?

Hubble, Bubble

Age 7 to 11
Challenge Level

Winifred Wytsh bought a box each of jelly babies, milk jelly bears, yellow jelly bees and jelly belly beans. In how many different ways could she make a jolly jelly feast with 32 legs?

Gift Stacks

Age 7 to 11
Challenge Level

Use the information to work out how many gifts there are in each pile.

Sums and Differences 1

Age 7 to 11
Challenge Level

This challenge focuses on finding the sum and difference of pairs of two-digit numbers.

Sums and Differences 2

Age 7 to 11
Challenge Level

Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?

The Dice Train

Age 7 to 11
Challenge Level

This dice train has been made using specific rules. How many different trains can you make?

Zios and Zepts

Age 7 to 11
Challenge Level

On the planet Vuv there are two sorts of creatures. The Zios have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zios and how many Zepts were there?

Sisters and Brothers

Age 7 to 11
Challenge Level

Cassandra, David and Lachlan are brothers and sisters. They range in age between 1 year and 14 years. Can you figure out their exact ages from the clues?

The Puzzling Sweet Shop

Age 5 to 11
Challenge Level

There were chews for 2p, mini eggs for 3p, Chocko bars for 5p and lollypops for 7p in the sweet shop. What could each of the children buy with their money?

Prison Cells

Age 7 to 11
Challenge Level

There are 78 prisoners in a square cell block of twelve cells. The clever prison warder arranged them so there were 25 along each wall of the prison block. How did he do it?

Oranges and Lemons

Age 7 to 11
Challenge Level

On the table there is a pile of oranges and lemons that weighs exactly one kilogram. Using the information, can you work out how many lemons there are?

Clever Keys

Age 7 to 11 Short
Challenge Level

On a calculator, make 15 by using only the 2 key and any of the four operations keys. How many ways can you find to do it?

Spell by Numbers

Age 7 to 11
Challenge Level

Can you substitute numbers for the letters in these sums?

Calendar Calculations

Age 7 to 11
Challenge Level

Try adding together the dates of all the days in one week. Now multiply the first date by 7 and add 21. Can you explain what happens?

Throw a 100

Age 7 to 11
Challenge Level

Can you score 100 by throwing rings on this board? Is there more than way to do it?

Abundant Numbers

Age 7 to 11
Challenge Level

48 is called an abundant number because it is less than the sum of its factors (without itself). Can you find some more abundant numbers?

Buckets of Thinking

Age 7 to 11
Challenge Level

There are three buckets each of which holds a maximum of 5 litres. Use the clues to work out how much liquid there is in each bucket.

Number Juggle

Age 7 to 11
Challenge Level

Fill in the missing numbers so that adding each pair of corner numbers gives you the number between them (in the box).

Arranging the Tables

Age 7 to 11
Challenge Level

There are 44 people coming to a dinner party. There are 15 square tables that seat 4 people. Find a way to seat the 44 people using all 15 tables, with no empty places.

On Target

Age 7 to 11
Challenge Level

You have 5 darts and your target score is 44. How many different ways could you score 44?

Magic Circles

Age 7 to 11
Challenge Level

Put the numbers 1, 2, 3, 4, 5, 6 into the squares so that the numbers on each circle add up to the same amount. Can you find the rule for giving another set of six numbers?

Special 24

Age 7 to 11
Challenge Level

Find another number that is one short of a square number and when you double it and add 1, the result is also a square number.

How Many Eggs?

Age 7 to 11
Challenge Level

Peter, Melanie, Amil and Jack received a total of 38 chocolate eggs. Use the information to work out how many eggs each person had.

A-magical Number Maze

Age 7 to 11
Challenge Level

This magic square has operations written in it, to make it into a maze. Start wherever you like, go through every cell and go out a total of 15!

A Mixed-up Clock

Age 7 to 11
Challenge Level

There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?

Adding Plus

Age 7 to 11
Challenge Level

Can you put plus signs in so this is true? 1 2 3 4 5 6 7 8 9 = 99 How many ways can you do it?

Machines

Age 7 to 11
Challenge Level

What is happening at each box in these machines?

Which Symbol?

Age 7 to 11
Challenge Level

Choose a symbol to put into the number sentence.

Sam's Quick Sum

Age 7 to 11
Challenge Level

What is the sum of all the three digit whole numbers?

Place Value as a Building Block for Developing Fluency in the Calculation Process

Age 5 to 11

This article for primary teachers encourages exploration of two fundamental ideas, exchange and 'unitising', which will help children become more fluent when calculating.

Today's Date - 01/06/2009

Age 5 to 11
Challenge Level

What do you notice about the date 03.06.09? Or 08.01.09? This challenge invites you to investigate some interesting dates yourself.

Being Resourceful - Primary Number

Age 5 to 11
Challenge Level

Number problems at primary level that require careful consideration.

Being Resilient - Primary Number

Age 5 to 11
Challenge Level

Number problems at primary level that may require resilience.

Sending Cards

Age 7 to 11
Challenge Level

This challenge asks you to investigate the total number of cards that would be sent if four children send one to all three others. How many would be sent if there were five children? Six?

Dice and Spinner Numbers

Age 7 to 11
Challenge Level

If you had any number of ordinary dice, what are the possible ways of making their totals 6? What would the product of the dice be each time?

Cows and Sheep

Age 7 to 11
Challenge Level

Use your logical reasoning to work out how many cows and how many sheep there are in each field.

Rabbits in the Pen

Age 7 to 11
Challenge Level

Using the statements, can you work out how many of each type of rabbit there are in these pens?

Dart Target

Age 7 to 11
Challenge Level

This task, written for the National Young Mathematicians' Award 2016, invites you to explore the different combinations of scores that you might get on these dart boards.

Magic Constants

Age 7 to 11
Challenge Level

In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?

The Number Crunching Machine

Age 7 to 11
Challenge Level

Put a number at the top of the machine and collect a number at the bottom. What do you get? Which numbers get back to themselves?

Oh! Harry!

Age 7 to 11
Challenge Level

A group of children are using measuring cylinders but they lose the labels. Can you help relabel them?