BIDMAS, BODMAS, PEMDAS – however you remember it, it’s all about the correct order of carrying out calculations. Put yourself to the test in this GCSE Maths quiz!
Maths isn’t as easy as reading a book – we can’t just do a calculation from left to right. Some operations have a higher priority than others, and so we need to know the correct order to do them in. BIDMAS doesn’t just apply to number problems, it crops up in algebra problems too, but you will be expected to know it without being told. It’s a good idea to write down each stage of working, showing what has changed and what’s stayed the same. This will help you keep the numbers in the correct place.
B is for brackets. If part of the calculation is wrapped up in brackets, work it out first.
Remember to apply BIDMAS to whatever is inside the bracket! A fraction bar acts like a bracket, so if there is more than one term in either the numerator or the denominator, work it out first.
I is for indices, or powers. It’s a good idea to know the first 12 square numbers, and the first few cube numbers too. If you are squaring a negative, remember that it becomes positive!
Multiplication and Division have the same priority and can be applied now.
Addition and Subtraction are last on the list, with the lowest priority. This doesn’t mean they aren’t important though! Take particular care if you are working with negative numbers.
The good news for you is that modern calculators recognise and apply BIDMAS, but you should check carefully that you have correctly entered a calculation. The bad news is that BIDMAS questions, like the one in this quiz, will come up in the Non-Calculator paper!