Fractions, Decimals and Perecentages

Question 1

What is 1/4 as a fraction?

Answer 1

0.25

Question 2

What is 1/4 as a percentage?

Answer 2

25%

Question 3

What is 1/5 as a fraction?

Answer 3

0.2

Question 4

What is 1/5 as a percentage?

Answer 4

20%

Question 5

What is 1/3 as a fraction?

Answer 5

0.33˙
(the ˙ means that the three recurs to infinity so it’s more like 0.33333333333…. forever)

Question 6

What is 1/3 as a percentage?

Answer 6

33.3˙ %

Question 7

What is 1/10 as a fraction and percentage?

Answer 7

0.1 fraction

10% percentage

Question 8

What is 1/8 as a fraction?

Answer 8

0.125

(This is half of a quarter which makes sense - instead of dividing 1 by 4, you’re dividing by 2x4 (8), so you end up with a number half as large)

Question 9

What is 1/8 as a percentage?

Answer 9

12.5%

Question 10

How do you calculate something as a percentage out of 100?

e.g. 42% of 70

Answer 10

First work out 1% (70/100) = 0.7

Then multiply percentage you want to find by the value you found for 1% (0.7 x 42) = 29.4

Question 11

How do you calculate a percentage if you are starting with an amount that is not 100% ?

e.g. A car is £26,000 after depreciating in value by 15%. What was its original price?

Answer 11

Figure out what percentage you currently have. In this case 100-15% = 85 of original value.

Current price/ Current percentage (26,000/85) = 305.88 <- This is 1% of the original cost.

1% x 100 = Original cost (305.88 X 100) = £30,588

This is a little larger than the amount in the question, which should reassure us we’re right.

Question 12

What are the top and bottom numbers of a fraction called?

Answer 12

Top number is the numerator, bottom is denominator, so in 1/4 the numerator is 1 and the denominator is 4.

Question 13

How do you multiply fractions?

Answer 13

Times the numerators together, then times the denominators. e.g. 1/2 x 1/4 = 1/8.

No need to find a common denominator when multiplying fractions.

Question 14

How do you divide fractions?

Answer 14

Fractions are a division sum all by themselves, and the easiest way to divide a fraction by another fraction is to swap the numerator and denominator of the fraction you are dividing BY and instead multiply the terms.

So if you were doing 1/2 ÷ 1/4 you could instead write 1/2 x 4/1, which is 1/2 x 4 and equals 2.

Question 15

What is 2/8 ÷ 3/4?

Answer 15

First, write it as a multiplication sum using the reciprocal.

2/8 x 4/3

Then simply times the numerators together, and do the same for the denominators

2 x 4 = 8
8 x 3 = 24 Giving us the fraction 8/24

This can be simplified as both terms are divisible by 8, giving a final answer of 1/3

Question 16

How do you add or subtract fractions?

Answer 16

First find a common denominator, and multiply by whatever necessary to reach this.

The either add or subtract the numerators depending on which one the question asks for.

Question 17

What is 1/3 + 2/5?

Answer 17

The common denominator between 1/3 and 2/5 is 15

1/3 x 5 = 5/15
2/5 x 3 = 6/15

5+6 = 11, giving and answer of 11/15 which cannot be simplified any further