Factors and multiples

There are 243 NRICH Mathematical resources connected to Factors and multiples
Remainders
problem

Remainders

Age
7 to 14
Challenge level
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I'm thinking of a number. My number is both a multiple of 5 and a multiple of 6. What could my number be?
Got It
problem

Got It

Age
7 to 14
Challenge level
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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.
Sets of Numbers
problem

Sets of Numbers

Age
7 to 11
Challenge level
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How many different sets of numbers with at least four members can you find in the numbers in this box?
Graphing Number Patterns
problem

Graphing Number Patterns

Age
7 to 11
Challenge level
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Does a graph of the triangular numbers cross a graph of the six times table? If so, where? Will a graph of the square numbers cross the times table too?
Two Primes Make One Square
problem

Two Primes Make One Square

Age
7 to 11
Challenge level
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Can you make square numbers by adding two prime numbers together?
Factor Lines
problem

Factor Lines

Age
7 to 14
Challenge level
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Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Shopping Basket
problem

Shopping Basket

Age
11 to 16
Challenge level
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The items in the shopping basket add and multiply to give the same amount. What could their prices be?
Scoring with Dice
problem

Scoring with Dice

Age
7 to 11
Challenge level
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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?
Divide it out
problem

Divide it out

Age
7 to 11
Challenge level
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What is the lowest number which always leaves a remainder of 1 when divided by each of the numbers from 2 to 10?
Multiplication Squares
problem

Multiplication Squares

Age
7 to 11
Challenge level
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Can you work out the arrangement of the digits in the square so that the given products are correct? The numbers 1 - 9 may be used once and once only.