Number

Question 1

Write 0.75 as a fraction

Answer 1

3/4

Question 2

Write 12/25 as a percentage

Answer 2

Aim to get the denominator over a power of 10.

Eg 12/25 = 48/100 therefore 48%

Question 3

What does BIDMAS mean?

Answer 3

Brackets
Indices
Division/Multiplication
Addition/subtraction

Question 4

Find 40% of £300

Answer 4

Calculator: 40/100 x 300 = £120

Non Calc:
Find 10% of 300 = 30
So 40% is 30 x 4 = £120

Question 5

What is the formula for percentage change?

Answer 5

Difference/original value x 100

Question 6

How to find the original value (reverse percentage)?

Answer 6

New amount / multiplier

Question 7

Write a 25% increase as a multiplier

Answer 7

1.25

(100% + 25% = 125%
125 / 100 = 1.25 )

Question 8

Write a 25% decrease as a multiplier

Answer 8

0.75

(100% - 25% = 75%
75 / 100 = 0.75 )

Question 9

Write the first 5 multiples of 6

Answer 9

6, 12, 18, 24, 30

Question 10

Write all the factors of 20

Answer 10

1, 20
2, 10
4, 5

Question 11

What is a prime number?

Answer 11

A number that has EXACTLY 2 factors (1 and itself)

Question 12

List the first 10 primes

Answer 12

2, 3, 5, 7, 11, 13, 17, 19, 23, 29

Question 13

List the first 15 square numbers

Answer 13

1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225

Question 14

List the first 6 cube numbers

Answer 14

1, 8, 27, 64, 125, 216

Question 15

How do you find the lowest common multiple?

Answer 15

List the multiples.

You want the lowest number that is common to both lists.

Eg LCM of 4 and 6

4, 8, 12
6, 12

12 is the LCM of 4 and 6.

Question 16

0.2 x 0.4

Answer 16

0.08

Question 17

0.07 x 0.3

Answer 17

0.021

Question 18

To convert a decimal to a percentage…

Answer 18

multiply by 100

Question 19

To convert a percentage to a decimal…

Answer 19

divide by 100

Question 20

Simplify 21 : 35 : 42

Answer 20

3 : 5 : 6

Question 21

Simplify the ratio 250m to 1km

Answer 21

1km = 1000m
So 250 : 10000
=> 1 : 4

Question 22

There are 6 dogs and 5 cats. Write the ratio of cats to dog.

Answer 22

Order of the sentence matters “cats to dogs”

5 : 6

Question 23

there is a ratio of 7 circles to 3 squares.

What fraction are squares?

Answer 23

3/10

The number of squares/total of all parts

Question 24

Share £42 in the ratio 3:4

Answer 24

Answer: 18 : 24
3:4  is 7 parts
7 parts = 42
1 part = 6 (42 divided by 7)
So multiply the parts by 6 to get
18:24

Question 25

Write 3 000 000 in standard form

Answer 25

3 x 10⁶

Question 26

Is this standard form?

52 x 10⁷

Answer 26

No, the first number must be between 1 and 10 (not including 10).
In standard form it would be 5.2 x 10^8

Question 27

Write 0.00047 in standard form

Answer 27

4.7 x 10‐⁴

Question 28

Write 8.5 x 10⁴ in ordinary form

Answer 28

85000

Question 29

Write 5.92 x 10‐⁷ in standard form

Answer 29

0.000000592