Converting

Question 0

How do you convert a fraction to a decimal?

Answer 0

Simply divide the top by the bottom. E.G: 1/8 = 1 divided by 8 = 0.125
E.G2: 3/10 = 3 divided by 10 = 0.3
E.G3: 9/20 = 9 divided by 20 = 0.45

Question 1

How do you convert a decimal to a fraction?

Answer 1

First you multiply the decimal by 100. Then put the answer over 100. Now simplify. E.G: 0.5 x 100 = 50 and then 50/100 = 1/2
E.G2: 0.56 x 100 = 56 and then 56/100 = 28/50 and 28/50 = 14/25

Question 2

How do you convert fractions to percentages?

Answer 2

First ensure that the denominator is 100 (because % = per cent = per hundred) (if it isn’t 100 already then make it 100, don’t forget, whatever you do to the top of the fraction you must do to the bottom and vice versa) and then put the top number as a percentage. E.G: 35/100 = 35%
E.G2: 12/25, multiply 25 by 4 to get 100. Multiply 12 by 4 as well and you get 48/100. 48/100 = 48%

Question 3

When converting fractions to percentages, if the bottom number isn’t a factor of 100, what do you do?

Answer 3

Covert the fraction to a decimal by dividing the top by the bottom. Multiply the decimal by 100 and put it as a percentage. E.G: 3/8 = 3 divided by 8 = 0.375, 0.375 x 100 = 375, 375%
E.G2: 4/6 = 4 divided by 6 = 0.66666667 = 66.666667, 66.666667% (round up to 66.67%)

Question 4

How do you convert a recurring decimal to a fraction?

Answer 4

If you were to trying to convert 0.54 (5 and 4 recurring) then you would imagine that 
x = 0.54
Multiply by 100
100x = 54.5454...
-x (remember, x = 0.54 (5 and 4 recurring)
99x = 54
Put 99 and 54 into a fraction
x = 54/99
Simplify if possible
6/11

E.G2: 0.73 (recurring)
x = 0.73
x100
100x = 73.7373...
-x
99x = 73
Put 99 and 73 into a fraction
73/99

E.G3: IMPORTANT: The amount digits in the number on top (e.g 7 = 1 digit, 77 = 2 digits, 777 = 3 digits, etc) must match the amount of 9s at the bottom.
0.7 (recurring)
x = 0.7
x10 (not 100 because 7 is just one digit, 0.77 would be multiplied by 100 and 0.777 would be multiplied by 1000)
10x = 7.77...
-x
9x = 7
Put 9 and 7 into a fraction
7/9

Question 5

How do you find a percentage of an amount?

Answer 5

There are many ways to do this. Using the example 23% of £60, first you can divide £60 by 100 to find 1% (which is 60p) then multiply the answer by 23 (because of 23%) which is 13.80 which is £13.80.
Another way is you can put the question into this form: (using this example it would be): (60x23) divided by 100
Which equals 13.80 or £13.80
One final way is to divide the percentage by 100 (0.23 in the case) and have that x 60
0.23 x 60 = 13.80 or £13.80

Question 6

How do you increase something by a percentage?

Answer 6

Find that percentage of the number and add it to the original amount.
E.G: £6.90 increased by 20%
20% of 6.90 = 1.38
£6.90 + £1.38 = £8.28

Question 7

How do you find what fraction of a number is another number (e.g: What fraction of 420 is 96?)

Answer 7

First put the numbers as a fraction with the second number at the top (e.g: 96/420) then simplify as much as possible (96/420 = 48/210 = 24/105 = 8/35) then you can express it as a decimal, then as a percentage (8/35 = 8 divided by 35 = 0.228 = 0.23 (rounded) = 23%).

Question 8

How do you find a percentage reduction?

Answer 8

First, with the example £900 is reduced to £765, you take the first number from the second (900 - 765 = 135). The percentage reduction is the reduction (£135) divided by the original amount (£900) then multiplied by 100%. So in this case it would be 135 divided by 900 (=0.15) then multiplied by 100% (15%).
E.G:
£750 reduced to £400
750 - 400 = 350
350 divided by 750 = 0.46666667 which = 0.47 = 47%

Question 9

How do you decrease something by a percentage?

Answer 9

Find the percentage of the amount and then take it away from the original amount.