MATHS Semester 2 Test 2 Revision

Factors and multiples Factors are numbers we can multiply together to get another number: A number can have MANY factors! Example: What are the factors of 12? 3 and 4 are factors of 12, because 3 × 4 = 12.  Also 2 × 6 = 12 so 2 and 6 are also factors of 12. And 1 × 12 = 12 so 1 and 12 are factors of 12 as well. So 1, 2, 3, 4, 6 and 12 are all factors of 12 A multiple is the result of multiplying a number by another number. Example: What are the multiples of 3? All the numbers in the 3 times tables, e.g. 3, 6, 9, 12, 15, 18, 21

Now you try these:

Prime numbers A Prime Number can be divided evenly only by 1 or itself. And it must be a whole number greater than 1. So a number which isn’t in any time tables apart from 1 or its own number. Here are the prime numbers between 1 and 30. 2 3 5 7 11 13 17 19 23 29

Now you try these:

Describing functions in algebra n function 1 function 2 algebraic equation 1  x 5 5 -2 3 5n - 2 2  x 3 + 1 3  12 -2 4n - 2 4  24 20 5  x7 40 7n + 5

Using simple ratios A ratio compares values. A ratio says how much of one thing there is compared to another thing. There are 3 blue squares to 1 yellow square A ratio can be scaled up: Here the ratio is also 3 blue squares to 1 yellow square, even though there are more squares.

So the ratio of flour to milk is 3 : 2 Example: A Recipe for pancakes uses 3 cups of flour and 2 cups of milk. So the ratio of flour to milk is 3 : 2 To make pancakes for a LOT of people we might need 4 times the quantity, so we multiply the numbers by 4: 3×4 : 2×4 = 12 : 8 In other words, 12 cups of flour and 8 cups of milk. The ratio is still the same, so the pancakes should be just as yummy.

Now you try these: 1. The ratio of cats to dogs at a pet care centre is 1:5. If there are 6 cats, how many dogs are there? __________ 2. The ratio of rice to water is 2:3. If we put 6 cups of rice, how many cups of water should we put? 3. The ratio of cars to motorbikes was 4:3. If there were 18 motorbikes, how many cars were there?

Calculating change. At the shops, I bought one book for £3.50 and a pencil case for £2.25. How much change did I get from £10.00. First we calculate how much we spent by adding: £3.50 +£2.25 £5.75 Then we calculate the change by subtracting: £10.00 -£ 5.75 £ 4.25

Now you try these: £2.67 £3.99 £5.25 £2.50 £1.20 £2.67 £3.99 £5.25 £2.50 £1.20 How much change would you get from £10 if you bought some flowers and some sweets? 2. How much change would you get from £10 if you bought some socks and a football? 3. One scarf costs £5.25. How much would 6 scarves cost?

Calculate the mean average? The mean average is calculated by adding all the amounts together and then dividing by the number of amounts. E.g. Number of goals scored in 6 games: 6 3 6 4 2 Mean average: 3 + 6 + 3 + 6 + 4 + 2 = 24 24 ÷ 6 = 4 So the mean average goals scored was 4.

Find the mean average: Number of T Shirts sold across 5 days: 3 8 5 3 1 Mean average = _____ 2. Test results across 4 weeks: 9 8 6 9 3. Number of absent days across 6 months: 5 8 2 0 3

Distance/time graph

For example: This person travelled 120 km in 2 hours quickly. Then he stopped for 2 hours. Then travelled another 30km in 2 hours, slowly.

How many miles did the man travel before he stopped? Now you try these: How many miles did the man travel before he stopped? For how long did he stop? How many miles did he travel altogether? How long was his total journey?

Pie charts Some year 6 children were asked about their favourite sport: What % of children preferred tennis? What % of children preferred swimming? Which was the most popular activity? Which was the least popular activity?