Surds
… are becoming more popular with GCSE maths questions although, rather than calculating, you’ll be expected to leave the answer in a ‘surd form.’ This usually means leaving as a square root, which cannot be reduced to a whole number. They are much more accurate than trying to calculate with decimals, although it’s quite difficult to give precise answers to the question ‘what are they used for?’
As a general comment:
- they can reduce the complexity of calculations, particularly for computer coding and engineering
- the term ‘surds’ is fairly new, it used to be ‘simplifying equations’ 🙂
Top Tips!
- Surds are just another way of showing a value the square root of 2 is more accurate (and easier to write) than 1.41421356237 etc
- Rationalise the denominator’ means make the bottom number whole
- ‘Show that’ means make your answer look the same
- You might need to do some extra work by using square numbers and multiples
- It might be useful to remember the square numbers 4, 9, 16, 25, 36, 49 and 100 as they’re the most commonly used
If you’d like to ask for any more detail, or you’re not sure about anything, please do ask a question in the comments section.
All best with your studies
Watch on YouTube
Write surds in the form – GCSE maths level 7 question
Surds “show that” question – level 7 GCSE maths new curriculum
Surds value of x question – GCSE mathematics level 7
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