1. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Adding fractions You can’t add them together until the bottoms (denominators) are the same What number can the denominators become? 12 as it is a multiple of both 3 and 4 + Our new denominator is now 12 Our new numerators are 8 and 3. Can you see why……

2. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Mean, Modes and Medians Mean: Add all up and then divide by how many 2+6+7+4+6+5+5+7+5+5+6+4+7+2+1= 72 72÷15= 4.8 Median: Put in order and find the middle 1, 2, 2, 4, 4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7 2 6 7 4 6 5 5 7 5 5 6 4 7 2 1 Here’s our data: Mode: Most Popular number 5 occurs the most here, so the mode is 5 Mean and Average are the same thing!

3. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Expanding brackets – everything inside gets multiplied by what’s outside Factorising – you need to find what all the terms divide by and put that outside the brackets Higher tier – you must be able to work with pairs of brackets too!

4. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Speed, distance and time Check your units are consistent so all times and distances are in the same units!

5. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Pythagoras’ Theorem (for when you know 2 sides of a right angled triangle and need the third) c (also called the hypotenuse) will always be the longest side After squaring: add to find the longest side, subtract for a short side and remember to square root at the end.

6. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Circles Tweedle dum tweedle dee circumference of a circle is pi times d. If you want to be prepared area of a circle is pi r squared. A = πr 2 C = πd r is the Radius d is the Diameter

7. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Rounding to Decimal Places: Rounding to one decimal place (second decimal figure decides if you round up) : 2.3547 rounds to 2.431.219 rounds to 31.2 0.7852 rounds to 0.8 Rounding to two decimal places (third decimal figure decides if you round up) : 2.3547 rounds to 2.35 31.219 rounds to 31.22

8. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) 100% 10% To find 10% divide original amount by 10 50% To find 50% half the amount 25% To find 25% divide amount by 4 1% To find 1% divide amount by 100 See if you can now find 20% and 95% of 160 Once you know 10% you can find 20%, 30%......... 90% by multiplying up or 5% by halving Remember if you have a calculator find 1% then multiply up to any percentage they ask for!

9. GCSE Mathematics 4 th of June 2015 (non-calculator) 8 th of June 2015 (calculator) Rounding to Significant Figures: Rounding to one significant figure: 178 rounds to 200 31.219 rounds to 30 0.7852 rounds to 0.8 Rounding to two significant figures: 6318 rounds to 6300 0.03682 rounds to 0.037 Start counting from the first non-zero digit. Normal rules for rounding still apply so look at the digit after the position you are rounding to.