Positive and negative numbers

article
Negative numbers

A brief history of negative numbers throughout the ages
article
Adding and subtracting positive and negative numbers

How can we help students make sense of addition and subtraction of negative numbers?
article
Making sense of positives and negatives

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

Age

11 to 14

Challenge level

If the odd numbers on two dice are made negative, which of the totals cannot be achieved?
problem
Minus one party

Age

11 to 14

Challenge level

Weekly Problem 47 - 2013
What is the value of the given expression?
problem
Pros and cons

Age

14 to 16

Challenge level

If p is a positive integer and q is a negative integer, which of these expressions is the greatest?
problem
Minus one two three

Age

14 to 16

Challenge level

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 ?
problem
Sum one special

Age

11 to 14

Challenge level

Three different integers have a sum of 1 and a product of 36 - what are they?
article
Positive about negative numbers

In this article for teachers, Liz Woodham describes resources on NRICH that can help primary-aged children get to grips with negative numbers.
problem
Swimming pool

Age

5 to 11

Challenge level

In this problem, we're investigating the number of steps we would climb up or down to get out of or into the swimming pool. How could you number the steps below the water?