Multiplying Fractions 2 3 4 5 x = © T Madas
4 5 2 3 8 15 = What is ? x 1 2 3 8 15 1 3 1 1 5 2 5 3 5 4 5 © T Madas
Finding something of something always means 3 4 2 7 What is of ? Finding something of something always means multiplication © T Madas
3 4 2 7 What is of ? © T Madas
3 4 2 7 What is of ? © T Madas
3 4 2 7 6 28 = What is of ? 6 28 © T Madas
To multiply two fractions: We multiply their numerators and denominators: 2 4 2 x 4 8 E.g. : x = = 3 5 3 x 5 15 2 3 2 x 3 6 x = = 5 7 5 x 7 35 a c a x c x = b d b x d © T Madas
To multiply two fractions: We multiply their numerators and denominators: 2 2 4 8 2 E.g. : x 4 = x = = 2 3 3 1 3 3 3 7 3 21 1 7 x = x = = 5 4 1 4 4 4 3 2 24 48 6 2 x 3 = x = = 6 7 1 7 7 7 2 3 5 11 55 7 1 x 2 = x = = 4 3 4 3 4 12 12 © T Madas
© T Madas
2 4 8 2 2 4 x = x = 3 7 21 3 9 27 2 3 6 3 4 3 12 3 x = = x = = 5 4 20 10 5 8 40 10 4 2 8 7 5 35 x = x = 5 9 45 9 6 54 4 5 20 2 4 5 20 5 x = = x = = 5 6 30 3 3 8 24 6 1 5 5 1 1 3 3 1 x = = x = = 5 8 40 8 6 5 30 10 © T Madas
5 4 20 2 2 4 x = x = 3 9 27 3 3 9 2 7 14 7 5 3 15 5 x = = x = = 5 4 20 10 6 7 42 14 4 4 16 1 7 7 x = x = 5 9 45 3 10 30 3 1 3 1 4 5 20 5 x = = x = = 10 18 180 60 3 12 36 9 1 8 8 2 5 3 15 1 x = = x = = 4 15 60 15 6 5 30 2 © T Madas
5 25 2 2 4 5 x = x = 9 9 3 7 21 2 9 18 9 5 4 20 5 x = = x = = 5 4 20 10 8 7 56 14 4 12 1 13 x 3 = x 13 = 5 5 6 6 3 5 15 1 8 5 40 5 x = = x = = 10 12 120 8 3 16 48 6 8 48 16 5 3 15 1 6 x = = x = = 15 15 5 9 20 180 12 © T Madas
© T Madas
2 4 8 2 2 4 x = x = 3 7 21 3 9 27 2 3 6 3 4 3 12 3 x = = x = = 5 4 20 10 5 8 40 10 4 2 8 7 5 35 x = x = 5 9 45 9 6 54 4 5 20 2 4 5 20 5 x = = x = = 5 6 30 3 3 8 24 6 1 5 5 1 1 3 3 1 x = = x = = 5 8 40 8 6 5 30 10 © T Madas
5 4 20 2 2 4 x = x = 3 9 27 3 3 9 2 7 14 7 5 3 15 5 x = = x = = 5 4 20 10 6 7 42 14 4 4 16 1 7 7 x = x = 5 9 45 3 10 30 3 1 3 1 4 5 20 5 x = = x = = 10 18 180 60 3 12 36 9 1 8 8 2 5 3 15 1 x = = x = = 4 15 60 15 6 5 30 2 © T Madas
5 25 2 2 4 5 x = x = 9 9 3 7 21 2 9 18 9 5 4 20 5 x = = x = = 5 4 20 10 8 7 56 14 4 12 1 13 x 3 = x 13 = 5 5 6 6 3 5 15 1 8 5 40 5 x = = x = = 10 12 120 8 3 16 48 6 8 48 16 5 3 15 1 6 x = = x = = 15 15 5 9 20 180 12 © T Madas
© T Madas
6 x 3 = x = = 23 cm2 A rectangle is 6⅝ cm long by 3½ cm wide. Calculate its area. to find the area: 5 8 1 2 6 x 3 = 3½ cm 53 8 7 2 x = 2 3 6⅝ cm 371 16 = 1 6 3 7 1 5 3 3 16 23 cm2 © T Madas
© T Madas
Adding the two figures: Ethan works day and night shifts in alternating weeks. He works: 5 days for 7¾ hours per day during his “day-shift” week. 5 nights for 6½ hours per night in his “night-shift” week. Calculate how many hours he works a fortnight. Week 1: 3 4 31 4 155 4 3 4 5 x 7 = 5 x = = 38 Week 2: 1 2 13 2 65 2 1 2 5 x 6 = 5 x = = 32 Adding the two figures: 3 4 1 2 1 4 1 4 38 + 32 = 70 + 1 = 71 Ethan works 71¼ hours every fortnight © T Madas
© T Madas
There is of the original amount left Tony drank of a full carton of orange juice. His sister Alice drank of what was left. 1 3 3 4 What fraction of the original amount of juice remains in the carton? Who drunk the most juice? [you must show full workings] If Tony drank of a full carton there is of a full carton left. Therefore Alice drank of of a full carton The operation that finds “something” of “something” is: multiplication 1 3 2 3 3 4 2 3 3 4 2 3 6 12 1 2 x = = Alice drunk half the carton [who drank the most?] x 2 x 3 1 3 1 2 2 6 3 6 5 6 There is of the original amount left 1 6 + = + = x 2 x 3 © T Madas
Let us solve the problem pictorially Tony drank of a full carton of orange juice. His sister Alice drank of what was left. 1 3 3 4 What fraction of the original amount of juice remains in the carton? Who drunk the most juice? [you must show full workings] Let us solve the problem pictorially Tony drunk of a full carton Alice drunk of what was left We are left with of a full carton Tony drunk of a full carton Alice drunk of a full carton Which is the same as 1 3 3 4 1 6 1 3 3 6 1 2 © T Madas
© T Madas