Factors : Numbers that divide into other numbers.

1. Revision: The Bare essentials Factors: Numbers that divide into other numbers. Look for pairs of numbers e.g. Factors of 12 are 1x12 2x6 3x4 = 1,2,3,4,6,12 Multiples: Answers to the times tables. First 5 multiples of 5 are 5,10,15,20,25. Square Numbers: Times a number by itself to give a square number. Can also form a square from it. Square numbers: 1,4,9,16,25,36,49,64,81,100 3x3=9 so 9 is a square number. 4x4=16 so 16 is a square number. Shown as 42 =16 Cube Numbers: Times a number by itself and then itself again. Cube numbers are: 1,8,27,64,125,216 3x3x3=27 so 27 is a cube number. Square Root: Opposite of squaring. Means what number times itself? = 2 (as 2x2=4) = 5 (as 5x5=25) = 8 (as 8x8=64) Prime Numbers: Only has 2 factors (numbers that go into them). Numbers that go in are only 1 and the number itself. Factors of 7 are only 1 and 7 so it’s a prime number so are 2,3,5,7,11,13,17,19… Even numbers can’t be prime as 2 goes into them. 1 is not a prime number. Rotational Symmetry: Order is how many times it looks the same in one complete rotation. Start 1 2 3 4 Order = 4 as looks the same 4 times.

2. Triangles: Equilateral Isosceles Scalene Same sides 2 sides same All different Same angles 2 angles same Rounding Off: 1 Significant figure = one number then zeros 234 to 1 sig fig = 200 ( 1 number then 0s) 48752 to 1 sig fig = 40000 Estimating: Round to 1 sig fig then do calculation. 234 x 65 = 200 x 70 = 14000 Make the numbers easy to use first even if you are allowed to use a calculator. Fractions of amounts: Divide amount by bottom number then times by top. of £150 = 150 ÷ 5 = £30 ( that’s of £150) then £30 x 2 = £60 ( ) If ½ or ¼ or ¾, then ÷ 2 for a half and ÷ 2 again for ¼. Percentage of Amounts: Always out of 100. Find 1% by dividing by 100, then multiply up. Find 12% of £150, Do £150 ÷ 100 = £1.50 ( 1%) then times up by 12 e.g £1.50 x 12 = £18. Remember ÷ 100 to give 1% then multiply it up. Remember to add amount on if it asks for the new price not just the increase. Fractions Decimals Percentages e.g. 0.125 12.5% 0.225 22.5% 60 60 60 Top ÷ bottom X 100 2 ÷ 16 X 100 9 ÷ 40 X 100

3. Angles add up to 180 º Angles add up to 360 º Probability: Always out of 1. Usually write as a fraction but also as a decimal or percentage. List outcomes to see how many there are. Flick a coin and role a dice: 1H 2H 3H 4H 5H 6H 1T 2T 3T 4T 5T 6T (12 outcomes) Coordinates: along first, then up or down. (x,y) Anglesacute obtuse reflex Congruent: Same shape, same size 90° Powers: Shows how many numbers to times together. 22 means 2 x 2 = 4 23means 2 x 2 x 2 = 8 24means 2 x 2 x 2 x 2 = 16 Not 2 x 4 Ratio: Shows how to share out things. Method 1 Method 2 Find how many shares there are. Count out the quantity in the ratio Divide amount by this total to find given until all used up then add up. the amount in one share then multiply out. Example: 20 sweets in the ratio 4:1 between Tom and Daniel 4 + 1 = 5 ( total number of shares) Tom Daniel 20 sweets ÷ 5 = 4 sweets ( number of sweets in one share) Tom gets 4 x 4 sweets = 16 sweets 16 sweets 4 sweets Daniel gets 1 x 4 sweets = 4 sweets 5 4 3,4 -3,2 3 2 1 -5 –4 –3 –2 –1 1 2 3 4 5 -2 3,-3 -3 -5,-4 -4 -5 180º 360°

4. width height length base Example Range = biggest – smallest 2,8,3,5,9,3 range=9-2=7 Mode = Most often or common one mode=3 Mean = Total of all numbers ÷ How many numbers you have mean=30÷6=5 Median = middle number (put in order first then cross off from each end) (If 2 middle numbers take the mean e.g. the number that would be between them) Can’t have 2 numbers for the median.2 3 3 5 8 9median = 4 Common Conversions to Learn FractionDecimalPercentage 0.5 50% 0.25 25% 0.75 75% 0.20 20% 0.33 33.3% 0.10 10% Perimeter: Distance round the outside. Imagine you are walking around it, how far have you gone all the way round? Area = length x width Area = ½ x base x height Volume: Space inside. Volume = length x width x height 4