# Subtraction

Subtraction is adding negative numbers to a number. Subtraction is not commutative (ie you cannot swap the question round: 4 - 5 ≠ 5 - 4.

Usually, when you subtract one number from another, the answer is less than the number with which you began. We call the answer the difference.

There are many ways of saying subtract: take away, minus, find the difference and to some extent, I suppose, find the range of.

## Historical dates

A self marking spreadsheet on number of years between several different events in history.

## Making 15

A self marking spreadsheet on making the number 15. There is also a sheet on subtracting two.

## Ten minus... Nine minus...

A self marking spreadsheet on subtracting numbers from 10, 9, 8 and 7 and then a selection of numbers.

## Number Grid Questions 1

Questions based on a 10 by 10 number grid. Questions include things like highest, lowest, sum of, difference between, products and locating the numbers in blanked out squares.

## Number Grid Questions 2

Questions based on a 10 by 10 number grid. Questions include things like highest, lowest, sum of, difference between, products and locating the numbers in blanked out squares.

## Subtraction using decomposition

A video going through four questions using decompostion to subtract one number from the other.

## Subtraction using decomposition

Problems using subtraction and taking information from tables.

## Subtraction using decomposition problem

A video involving finding the difference in scores between two football teams. Unfortunately, the numbers are made up... but we can dream.

## Ten minus... Twenty minus...

A self marking spreadsheet on subtracting numbers from 10, 20, 30, 40 and 50.

## Subtraction

A self marking spreadsheet on subtracting HTU, ThHTU and decimals.