To square a number you multiply it by itself. For example 3² =3×3=9

To cube a number you multiply it by itself three times. So 3³=3x3x3=27

If you are studying GCSE it is very helpful to learn the common squares and cubes to save you time in the non calculator exam. This exercise will help you do that-don’t be tempted to use a calculator! For Functional Skills students you can use a calculator. Look for the x² and x³ buttons on your scientific calculator and use these.

Each time you do this exercise you will get a different selection of questions. To do it again click the refresh icon on your browser. Find as many different calculators as you can. Your phone, your computer, the one in the back of the overflowing drawer in the hall. Then try this sum on all of them.

# 4+ 7 x 3

Do all the calculators give the same answer? What is the correct answer?

If you have a cheap four function calculator you will have got the answer 33, because it always calculates in the order you enter the sum. Unfortunately this is not mathematically correct!

If you used a scientific calculator you will have got the answer 25 which is correct. Scientific calculators understand the correct order to do calculations. Multiplication is more important than addition, so this comes first.

So how do we know what order to do calculations in? We use a rule called BIDMAS.

# S ubtraction –

Always do brackets first. Then do any indices (like 2 squared or square root of 16). Some people refer to BODMAS where the O stands for “of”.) Division and multiplication come next (these have equal priority). Last is additions and subtractions (also equal priority)

Try this interactive worksheet to see if you’ve got it.  Click here to download this Level 2 Functional Maths worksheet, Don’t always believe what you read in the newspaper.
It concerns how much money you can save by spending less time in the shower.