Other tags that relate to Which Numbers? (1)
Divisibility. Selecting and using information. Factors and multiples. Prime numbers. Odd and even numbers. Generalising. Working systematically. Multiplication & division. Addition & subtraction. Making and testing hypotheses.There are 227 results
Broad Topics > Calculations and Numerical Methods > Addition & subtraction
Score
Age 11 to 14
Challenge Level
There are exactly 3 ways to add 4 odd numbers to get 10. Find all the ways of adding 8 odd numbers to get 20. To be sure of getting all the solutions you will need to be systematic. What about. . . .
Marvellous Matrix
Age 7 to 11
Challenge Level
Follow the directions for circling numbers in the matrix. Add all the circled numbers together. Note your answer. Try again with a different starting number. What do you notice?
Neighbours
Age 7 to 11
Challenge Level
In a square in which the houses are evenly spaced, numbers 3 and 10 are opposite each other. What is the smallest and what is the largest possible number of houses in the square?
Number Daisy
Age 11 to 14
Challenge Level
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?
Take Three Numbers
Age 7 to 11
Challenge Level
What happens when you add three numbers together? Will your answer be odd or even? How do you know?
Making Maths: Double-sided Magic Square
Age 7 to 14
Challenge Level
Make your own double-sided magic square. But can you complete both sides once you've made the pieces?
Code Breaker
Age 7 to 11
Challenge Level
This problem is based on a code using two different prime numbers less than 10. You'll need to multiply them together and shift the alphabet forwards by the result. Can you decipher the code?
Cinema Problem
Age 11 to 14
Challenge Level
A cinema has 100 seats. Show how it is possible to sell exactly 100 tickets and take exactly £100 if the prices are £10 for adults, 50p for pensioners and 10p for children.
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?
Escape from the Castle
Age 7 to 11
Challenge Level
Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?
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?
Scoring with Dice
Age 7 to 11
Challenge Level
I throw three dice and get 5, 3 and 2. Add the scores on the three dice. What do you get? Now multiply the scores. What do you notice?
Double Digit
Age 11 to 14
Challenge Level
Choose two digits and arrange them to make two double-digit numbers. Now add your double-digit numbers. Now add your single digit numbers. Divide your double-digit answer by your single-digit answer. . . .
Prompt Cards
Age 7 to 11
Challenge Level
These two group activities use mathematical reasoning - one is numerical, one geometric.
Number Tracks
Age 7 to 11
Challenge Level
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
Odds and Threes
Age 7 to 11
Challenge Level
A game for 2 people using a pack of cards Turn over 2 cards and try to make an odd number or a multiple of 3.
Adding All Nine
Age 11 to 14
Challenge Level
Make a set of numbers that use all the digits from 1 to 9, once and once only. Add them up. The result is divisible by 9. Add each of the digits in the new number. What is their sum? Now try some. . . .
Number Differences
Age 7 to 11
Challenge Level
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?
Being Resilient - Primary Number
Age 5 to 11
Challenge Level
Number problems at primary level that may require resilience.
Being Collaborative - Primary Number
Age 5 to 11
Challenge Level
Number problems at primary level to work on with others.
Magic Vs
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?
Book Codes
Age 7 to 11
Challenge Level
Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?
Two Primes Make One Square
Age 7 to 11
Challenge Level
Can you make square numbers by adding two prime numbers together?
Making Pathways
Age 7 to 11
Challenge Level
Can you find different ways of creating paths using these paving slabs?
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!
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.
Calendar Patterns
Age 7 to 11
Challenge Level
In this section from a calendar, put a square box around the 1st, 2nd, 8th and 9th. Add all the pairs of numbers. What do you notice about the answers?
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?
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?
Street Sequences
Age 5 to 11
Challenge Level
Investigate what happens when you add house numbers along a street in different ways.
Diagonal in a Spiral
Age 7 to 11
Challenge Level
Investigate the totals you get when adding numbers on the diagonal of this pattern in threes.
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?
Sort Them Out (2)
Age 7 to 11
Challenge Level
Can you each work out the number on your card? What do you notice? How could you sort the cards?
Up, Down, Flying Around
Age 11 to 14
Challenge Level
Play this game to learn about adding and subtracting positive and negative numbers
Fingers and Hands
Age 7 to 11
Challenge Level
How would you count the number of fingers in these pictures?
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?
How Much Did it Cost?
Age 7 to 11
Challenge Level
Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.
Numbered Cars
Age 7 to 11
Challenge Level
I was looking at the number plate of a car parked outside. Using my special code S208VBJ adds to 65. Can you crack my code and use it to find out what both of these number plates add up to?
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?
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?
All Seated
Age 7 to 11
Challenge Level
Look carefully at the numbers. What do you notice? Can you make another square using the numbers 1 to 16, that displays the same properties?
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?
Have You Got It?
Age 11 to 14
Challenge Level
Can you explain the strategy for winning this game with any target?
Magic Triangle
Age 7 to 11
Challenge Level
Place the digits 1 to 9 into the circles so that each side of the triangle adds to the same total.
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?
How Old?
Age 7 to 11
Challenge Level
Cherri, Saxon, Mel and Paul are friends. They are all different ages. Can you find out the age of each friend using the information?
It's All about 64
Age 7 to 11
Challenge Level
Write the numbers up to 64 in an interesting way so that the shape they make at the end is interesting, different, more exciting ... than just a square.
Bean Bags for Bernard's Bag
Age 7 to 11
Challenge Level
How could you put eight beanbags in the hoops so that there are four in the blue hoop, five in the red and six in the yellow? Can you find all the ways of doing this?
NRICH is part of the family of activities in the Millennium Mathematics Project.