Addition and subtraction

There are 338 NRICH Mathematical resources connected to Addition and subtraction
Throw a 100
problem

Throw a 100

Age
7 to 11
Challenge level
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Can you score 100 by throwing rings on this board? Is there more than way to do it?
Rocco's Race
problem

Rocco's Race

Age
7 to 11
Challenge level
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Rocco ran in a 200 m race for his class. Use the information to find out how many runners there were in the race and what Rocco's finishing position was.
Super Shapes
problem

Super Shapes

Age
7 to 11
Challenge level
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The value of the circle changes in each of the following problems. Can you discover its value in each problem?
Twenty Divided into Six
problem

Twenty Divided into Six

Age
7 to 11
Challenge level
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Katie had a pack of 20 cards numbered from 1 to 20. She arranged the cards into 6 unequal piles where each pile added to the same total. What was the total and how could this be done?
Amy's Dominoes
problem

Amy's Dominoes

Age
7 to 11
Challenge level
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Amy has a box containing domino pieces but she does not think it is a complete set. Which of her domino pieces are missing?
Calendar Calculations
problem

Calendar Calculations

Age
7 to 11
Challenge level
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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?
Mrs Beeswax
problem

Mrs Beeswax

Age
5 to 7
Challenge level
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In how many ways could Mrs Beeswax put ten coins into her three puddings so that each pudding ended up with at least two coins?
Eleven
problem

Eleven

Age
11 to 14
Challenge level
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Replace each letter with a digit to make this addition correct.
Next Number
problem

Next Number

Age
7 to 11
Challenge level
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Find the next number in this pattern: 3, 7, 19, 55 ...
Add 3 Dice
problem

Add 3 Dice

Age
7 to 11
Challenge level
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Three dice are placed in a row. Find a way to turn each one so that the three numbers on top of the dice total the same as the three numbers on the front of the dice. Can you find all the ways to do this?