Surds – ‘show that’ and ‘write in the form’ questions – mid-level

 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