The four operations of fractions And more information about fractions By Olive Gibbon

Adding fractions together To add fractions together, first find the lowest common factor that both denominators go into (if the denominators are the same then leave them). e.g. 2/3 and 1/2 denominators both go into 6. The answer is the new denominator. Then if you changed it work out how many times bigger you made the denominator and make the numerator that many times bigger. E.g. if you trippled it, it would get 3 more times bigger, if you doubled it you would make it 2 times bigger.

Subtracting fractions from each other To subtract fractions, first find the lowest common factor that both denominators go into (if the denominators are the same then leave them) e.g. 3/8-5/9 both go into 72, so their new denominator is 72, but you have multiplied the denominators you need to multiply the numerators by how many times you multiplied the denominator. So the numerators for this fraction would be 27 and 40. Now subtract the numerators from each other. So the answer for this fraction is 13/72. To subtract fractions, first find the lowest common factor that both denominators go into (if the denominators are the same then leave them) e.g. 3/8-5/9 both go into 72, so their new denominator is 72, but you have multiplied the denominators you need to multiply the numerators by how many times you multiplied the denominator. So the numerators for this fraction would be 27 and 40. Now subtract the numerators from each other. So the answer for this fraction is 13/72.

Multiplying fractions To multiply fractions, first multiply the two numerators together to get the new numerator. Then multiply the two denominators together to get the new denominator. E.g. 7/8 x 9/10 = 63/80 If it is an improper fraction, you have to work out how many times the denominator goes into the numerator for your whole number. Then do how much remainder there was for the numerator of the fraction. Then put the old denominator for the denominator of your new fraction. If it is an improper fraction, you have to work out how many times the denominator goes into the numerator for your whole number. Then do how much remainder there was for the numerator of the fraction. Then put the old denominator for the denominator of your new fraction. E.g. 63/14 (an improper fraction) = 4 and 7/14 E.g. 63/14 (an improper fraction) = 4 and 7/14 To simplify fractions press here. To simplify fractions press here.here.

Dividing fractions First turn your second fraction upside down (e.g. 1/2 + 3/4 = 1/2 + 4/3). Then multiply the fractions together using the multiplying fractions method. First turn your second fraction upside down (e.g. 1/2 + 3/4 = 1/2 + 4/3). Then multiply the fractions together using the multiplying fractions method.

Multiplying a whole number by a fraction First put the whole number over 1 and multiply the two fractions. If you get an improper fraction then work out how many times the denominator goes into the numerator and if there is any remainder you put the remainder over the denominator of the answer and then that is your answer. First put the whole number over 1 and multiply the two fractions. If you get an improper fraction then work out how many times the denominator goes into the numerator and if there is any remainder you put the remainder over the denominator of the answer and then that is your answer. E.g. 7/14 x 9/1 = 63/14 63/14 = 4 and 7/14 E.g. 7/14 x 9/1 = 63/14 63/14 = 4 and 7/14

Dividing a whole number by a fraction First you need to put the whole number over 1. Then turn the second fraction upside down and multiply the fractions together. If you get a remainder then do the same as you did when multiplying a fraction by a whole number. First you need to put the whole number over 1. Then turn the second fraction upside down and multiply the fractions together. If you get a remainder then do the same as you did when multiplying a fraction by a whole number. E.g. 10/1 divided by 3/4 = 10/1 divided by 4/3 = 40/3 = 13 and 1/3 E.g. 10/1 divided by 3/4 = 10/1 divided by 4/3 = 40/3 = 13 and 1/3

Simplifying fractions To simplify a fraction you need to find the highest common factor (HCF) and then for your numerator you do how many times the factor goes into the numerator. Then how many times that number goes into the denominator for the new denominator. E.g. 16/40 = 2/5 To simplify a fraction you need to find the highest common factor (HCF) and then for your numerator you do how many times the factor goes into the numerator. Then how many times that number goes into the denominator for the new denominator. E.g. 16/40 = 2/5

Here are some tricky questions to test you on your knowledge 3 x 1/7 = A. 6/6 B. 3/7 C. 9/25 A. 6/6 B. 3/7 C. 9/25A. 6/6 B. 3/7 C. 9/25 3/7 + 1/2 = A. 4/4 B. 14/14 C. 9/14 A. 4/4 B. 14/14 C. 9/14A. 4/4 B. 14/14 C. 9/14 9/12 – 1/3 = A. 1/3 B. 9/14 C. 5/12 A. 1/3 B. 9/14 C. 5/12A. 1/3 B. 9/14 C. 5/12 I hope you got them all right!

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