Addition and subtraction

There are 355 NRICH Mathematical resources connected to Addition and subtraction
Consecutive Numbers
problem
Favourite

Consecutive numbers

Age
7 to 14
Challenge level
filled star empty star empty star

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

2, 4, 6, 8
problem
Favourite

2, 4, 6, 8

Age
5 to 7
Challenge level
filled star filled star filled star
Using the cards 2, 4, 6, 8, +, - and =, what number statements can you make?
Neighbours
problem
Favourite

Neighbours

Age
7 to 11
Challenge level
filled star filled star empty star
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?
Reach 100
problem
Favourite

Reach 100

Age
7 to 11
Challenge level
filled star filled star empty star

Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.

Cinema Problem
problem
Favourite

Cinema problem

Age
11 to 14
Challenge level
filled star empty star empty star

A cinema has 100 seats. How can ticket sales make £100 for these different combinations of ticket prices?

Domino Pick
problem
Favourite

Domino pick

Age
5 to 7
Challenge level
filled star filled star empty star
Are these domino games fair? Can you explain why or why not?
Even and odd
problem
Favourite

Even and odd

Age
5 to 7
Challenge level
filled star empty star empty star
This activity is best done with a whole class or in a large group. Can you match the cards? What happens when you add pairs of the numbers together?
Countdown
game
Favourite

Countdown

Here is a chance to play a version of the classic Countdown Game.

Birthday Cakes
problem
Favourite

Birthday cakes

Age
5 to 7
Challenge level
filled star filled star empty star
Jack's mum bought some candles to use on his birthday cakes and when his sister was born, she used them on her cakes too. Can you use the information to find out when Kate was born?
Highest and Lowest
problem
Favourite

Highest and lowest

Age
7 to 11
Challenge level
filled star empty star empty star
Put operations signs between the numbers 3 4 5 6 to make the highest possible number and lowest possible number.