# Four Operations

GCSELevel 1-3Cambridge iGCSEEdexcel iGCSE

## The Four Operations

The four operations include addition, subtraction, multiplication, and division.

Addition: operation to find the total of two or more numbers.

Subtraction: operation to find the difference between two numbers.

Multiplication: operation to find the product of two or more numbers.

Division: operation to split a number into equal parts.

Simple addition questions, like $5+11$, can be easily calculated ourselves or by using a calculator and typing in $5+11=$ giving us $16$.

We may come across more complicated questions, such as:

If Sally has $\text{£}12$, and for her birthday she is given $\text{£}230$ from her mum, $\text{£}162$ from her dad, and $\text{£}51$ from her brother, how much money does she now have?

We can similarly work this out by typing the following into our calculator:

$12+230+162+51=\text{£}455$

Level 1-3GCSECambridge iGCSEEdexcel iGCSE

## Subtraction

Similarly to addition, we can use our calculator to work out subtraction questions, for example:

If Sally has $\text{£}455$, and she spends $\text{£}80$ on shoes, $\text{£}118$ on jumpers, and $\text{£}66$ on jewellery, how much money would she have remaining?

We can work this out by typing the following into our calculator:

$455-80-118-66=\text{£}191$.

Level 1-3GCSECambridge iGCSEEdexcel iGCSE

## Multiplication

Simple multiplication questions, like $4\times5$, can be easily calculated ourselves or  by using a calculator and typing in $4\times5=$, giving us $20$.

We may come across more complicated questions, such as:

Freddie buys $6$ chocolate bars for $55\text{ p}$ each, how much does he spend in total?

We can similarly work this out by typing the following into our calculator:

$6\times55=330\text{ p}$.

Level 1-3GCSECambridge iGCSEEdexcel iGCSE

## Division

Similarly to multiplication, we can use our calculator to work out division questions, for example:

Freddie spends $605\text{ p}$ on chocolate bars. Each chocolate bar costs $55\text{ p}$, how many chocolate bars does Freddie buy?

We can similarly work this out by typing the following into our calculator:

$605\div55=11$ chocolate bars.

Level 1-3GCSECambridge iGCSEEdexcel iGCSE

## Example 1: Simple Operations

Use your calculator to work out these four operation questions:

a) $16+12+31+40$

b) $109-34-12-9$

c) $3\times5\times9\times18$

d) $100\div4\div5$

[4 marks]

a) By typing the sum into a calculator:

$16+12+31+40=99$

b) By typing the sum into a calculator:

$109-34-12-9=54$

c) By typing the sum into a calculator:

$3\times5\times9\times18=2430$

d) By typing the sum into a calculator:

$100\div4\div5=5$

Level 1-3GCSECambridge iGCSEEdexcel iGCSE

## Example 2: Applied Operations

Bart is going to a supermarket. He buys a bag of kiwis for $\text{£}3$, some yoghurts for $\text{£}4$ and $6$ toothbrushes each priced at $\text{£}1$.

By using multiplication and addition, calculate how much money Bart spent overall at the supermarket.

[3 marks]

Firstly, we can work out how much he spent in total on toothbrushes by multiplying the price by the number of toothbrushes bought:

$\text{£}1\times6=\text{£}6$

Now, we can add up everything he bought to find his total:

$\text{£}6+\text{£}3+\text{£}4=\text{£}13$

Level 1-3GCSECambridge iGCSEEdexcel iGCSE

## Four Operations Example Questions

Monday: $55$

Tuesday: $55+4=59$

Wednesday: $59+11=70$

Thursday: $70-28=42$

Therefore, she had $42$ stamps remaining.

Gold Standard Education

We can firstly use addition to calculate the total cost for all $4$ friends:

$\text{£}600+\text{£}1800+\text{£}300=\text{£}2700$

We can then divide this by $4$ to calculate how much each person spent.

$\text{£}2700\div4=\text{£}675$

Gold Standard Education

Firstly, we can share the $160$ pens between the $32$ students using division:

$160\div32=5$

So, each child has $5$ colouring pens.

Then, each child loses $2$ pens:

$5-2=3$

Therefore, by the end of the day, each student has $3$ colouring pens.