This article suggests some ways of making sense of calculations involving positive and negative numbers.

How can we help students make sense of addition and subtraction of negative numbers?

Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?

In this game the winner is the first to complete a row of three. Are some squares easier to land on than others?

Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?

What is the smallest number of answers you need to reveal in order to work out the missing headers?

Investigate different ways of making £5 at Charlie's bank.

Play this game to learn about adding and subtracting positive and negative numbers

Different combinations of the weights available allow you to make different totals. Which totals can you make?

First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.

The idea of this game is to add or subtract the two numbers on the dice and cover the result on the grid, trying to get a line of three. Are there some numbers that are good to aim for?

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

Imagine a very strange bank account where you are only allowed to do two things...

Substitute -1, -2 or -3, into an algebraic expression and you'll get three results. Is it possible to tell in advance which of those three will be the largest ?

This article -useful for teachers and learners - gives a short account of the history of negative numbers.

How many intersections do you expect from four straight lines ? Which three lines enclose a triangle with negative co-ordinates for every point ?