Other tags that relate to What Do You Need?
Working systematically. Divisibility. Addition & subtraction. Odd and even numbers. Games. Factors and multiples. Place value. Multiplication & division. Mathematical reasoning & proof. Generalising.There are 153 results
Broad Topics > Calculations and Numerical Methods > Multiplication & division
Product Sudoku
Age 11 to 16
Challenge Level
The clues for this Sudoku are the product of the numbers in adjacent squares.
Multiples Sudoku
Age 11 to 14
Challenge Level
Each clue in this Sudoku is the product of the two numbers in adjacent cells.
A First Product Sudoku
Age 11 to 14
Challenge Level
Given the products of adjacent cells, can you complete this Sudoku?
The Remainders Game
Age 7 to 14
Challenge Level
Play this game and see if you can figure out the computer's chosen number.
Ones Only
Age 11 to 14
Challenge Level
Find the smallest whole number which, when mutiplied by 7, gives a product consisting entirely of ones.
Legs Eleven
Age 11 to 14
Challenge Level
Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?
Thirty Six Exactly
Age 11 to 14
Challenge Level
The number 12 = 2^2 × 3 has 6 factors. What is the smallest natural number with exactly 36 factors?
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.
Times Right
Age 11 to 16
Challenge Level
Using the digits 1, 2, 3, 4, 5, 6, 7 and 8, mulitply a two two digit numbers are multiplied to give a four digit number, so that the expression is correct. How many different solutions can you find?
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. . . .
What Is the Question?
Age 11 to 16
Challenge Level
These pictures and answers leave the viewer with the problem "What is the Question". Can you give the question and how the answer follows?
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. . . .
Factoring Factorials
Age 11 to 14
Challenge Level
Find the highest power of 11 that will divide into 1000! exactly.
Eminit
Age 11 to 14
Challenge Level
The number 8888...88M9999...99 is divisible by 7 and it starts with the digit 8 repeated 50 times and ends with the digit 9 repeated 50 times. What is the value of the digit M?
Powerful Factorial
Age 11 to 14
Challenge Level
6! = 6 x 5 x 4 x 3 x 2 x 1. The highest power of 2 that divides exactly into 6! is 4 since (6!) / (2^4 ) = 45. What is the highest power of two that divides exactly into 100!?
Journeys on the Gattegno Tens Chart
Age 5 to 11
Alf describes how the Gattegno chart helped a class of 7-9 year olds gain an awareness of place value and of the inverse relationship between multiplication and division.
Alphabetti Sudoku
Age 11 to 16
Challenge Level
This Sudoku requires you to do some working backwards before working forwards.
Square Subtraction
Age 7 to 11
Challenge Level
Look at what happens when you take a number, square it and subtract your answer. What kind of number do you get? Can you prove it?
Please Explain
Age 11 to 14
Challenge Level
Visitors to Earth from the distant planet of Zub-Zorna were amazed when they found out that when the digits in this multiplication were reversed, the answer was the same! Find a way to explain. . . .
Oh! Hidden Inside?
Age 11 to 14
Challenge Level
Find the number which has 8 divisors, such that the product of the divisors is 331776.
Funny Factorisation
Age 11 to 16
Challenge Level
Using the digits 1 to 9, the number 4396 can be written as the product of two numbers. Can you find the factors?
Multiply the Addition Square
Age 11 to 14
Challenge Level
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?
Going Round in Circles
Age 11 to 14
Challenge Level
Mathematicians are always looking for efficient methods for solving problems. How efficient can you be?
Why 8?
Age 11 to 14
Challenge Level
Choose any four consecutive even numbers. Multiply the two middle numbers together. Multiply the first and last numbers. Now subtract your second answer from the first. Try it with your own. . . .
Repeaters
Age 11 to 14
Challenge Level
Choose any 3 digits and make a 6 digit number by repeating the 3 digits in the same order (e.g. 594594). Explain why whatever digits you choose the number will always be divisible by 7, 11 and 13.
Integrated Product Sudoku
Age 11 to 16
Challenge Level
This Sudoku puzzle can be solved with the help of small clue-numbers on the border lines between pairs of neighbouring squares of the grid.
Gabriel's Problem
Age 11 to 14
Challenge Level
Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?
Remainders
Age 7 to 14
Challenge Level
I'm thinking of a number. My number is both a multiple of 5 and a multiple of 6. What could my number be?
Missing Multipliers
Age 7 to 14
Challenge Level
What is the smallest number of answers you need to reveal in order to work out the missing headers?
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?
Being Resilient - Primary Number
Age 5 to 11
Challenge Level
Number problems at primary level that may require resilience.
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.
Method in Multiplying Madness?
Age 7 to 14
Challenge Level
Watch our videos of multiplication methods that you may not have met before. Can you make sense of them?
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?
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?
Can You Make 100?
Age 11 to 14
Challenge Level
How many ways can you find to put in operation signs (+ - x Ă·) to make 100?
Fair Feast
Age 5 to 11
Challenge Level
Here is a picnic that Petros and Michael are going to share equally. Can you tell us what each of them will have?
Wild Jack
Age 7 to 11
Challenge Level
A game for 2 or more players with a pack of cards. Practise your skills of addition, subtraction, multiplication and division to hit the target score.
Asteroid Blast
Age 7 to 11
Challenge Level
A game for 2 people. Use your skills of addition, subtraction, multiplication and division to blast the asteroids.
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?
X Is 5 Squares
Age 7 to 11
Challenge Level
Can you arrange 5 different digits (from 0 - 9) in the cross in the way described?
As Easy as 1,2,3
Age 11 to 14
Challenge Level
When I type a sequence of letters my calculator gives the product of all the numbers in the corresponding memories. What numbers should I store so that when I type 'ONE' it returns 1, and when I type. . . .
Compare the Calculations
Age 7 to 11
Challenge Level
Can you put these four calculations into order of difficulty? How did you decide?
Making Pathways
Age 7 to 11
Challenge Level
Can you find different ways of creating paths using these paving slabs?
Ducking and Dividing
Age 7 to 11
Challenge Level
Your vessel, the Starship Diophantus, has become damaged in deep space. Can you use your knowledge of times tables and some lightning reflexes to survive?
X Marks the Spot
Age 11 to 14
Challenge Level
When the number x 1 x x x is multiplied by 417 this gives the answer 9 x x x 0 5 7. Find the missing digits, each of which is represented by an "x" .
Tom's Number
Age 7 to 11
Challenge Level
Work out Tom's number from the answers he gives his friend. He will only answer 'yes' or 'no'.
NRICH is part of the family of activities in the Millennium Mathematics Project.