Maths 1º ESO FRACTIONS 2 Name:……………………………………………………………………………………………………………………………… 1) How much is: a) A quarter of c) A fifth of
1 ? 4
1 ? 5 3 d) A third of ? 5
(1 point)
b) Half of
5 ? 8
2)Calculate and simplify: a)
1 9 − +1 = 15 10
b)
2 ⎛ 1 2⎞ − ⎜ + ⎟ ×2 = 3 ⎝2 3⎠
c)
2 6 7 2 × × × = 5 4 10 14
d)
3 5 4 3 ÷ − ÷ = 7 14 5 2
(5 points)
⎛1 1⎞ ⎛1 1⎞ + ⎟×⎜ − ⎟ = ⎝2 3⎠ ⎝2 5⎠
e) ⎜
3) A man had ninety melons. He gave two fifths to his father and 2/15 to a friend. How many melons did he have left? (1 point)
4) Elisabeth buys 4/6 lbs of grapes and 5/7 lbs of oranges. Does she buy more grapes or more oranges? How many lbs of fruit does she buy in total? (1 point)
5)A teacher has marked 2/7 of his exams with a red marker and 1/4 with a blue one. If he still has 52 exams to mark, how many exams did he start with? (1 point)
6) In a 5600 m2 farm, they grow maize, onions and potatoes. They use three eighths of the farm for growing maize and two fifths of the remainder for growing onions, how many square metres do they use for growing potatoes? (1 point)
Maths 1º ESO SOLUTIONS 1) How much is: a) A quarter of
c) A fifth of
1 1 1 1 ? ⋅ = 4 4 4 16
5 1 5 1 ? ⋅ = 8 5 8 8
b) Half of
1 1 1 1 ? ⋅ = 5 2 5 10
d) A third of
3 1 3 1 ? ⋅ = 5 3 5 5
2)Calculate and simplify: a)
1 9 2 27 30 5 1 − + = = − +1 = 30 30 30 30 6 15 10
b)
2 ⎛ 1 2⎞ 2 ⎛3 4⎞ 2 7 2 7 5 − ⎜ + ⎟ ×2 = − ⎜ + ⎟ ×2 = − ×2 = − = − 3 ⎝2 3⎠ 3 ⎝6 6⎠ 3 6 3 3 3
c)
2 6 7 2 2×2×3× 7 ×2 3 = × × × = 5 4 10 14 5 × 2 × 2 × 2 × 5 × 2 × 7 50
d)
3 5 4 3 3 × 14 4 × 2 6 8 18 8 10 2 − = − = − = = ÷ − ÷ = 7 14 5 2 5 × 7 5 × 3 5 15 15 15 15 3 5×3 1 ⎛1 1 ⎞ ⎛1 1 ⎞ ⎛3 2⎞ ⎛ 5 2 ⎞ 5 3 + ⎟×⎜ − ⎟ = ⎜ + ⎟×⎜ − ⎟ = × = = ⎝ 2 3 ⎠ ⎝ 2 5 ⎠ ⎝ 6 6 ⎠ ⎝ 10 10 ⎠ 6 10 6 × 10 4
e) ⎜
3) A man had ninety melons. He gave two fifths to his father and 2/15 to a friend. How many melons did he have left?
7 × 90 2 2 6 2 8 7 = 42 melons + = + = he have left of 90 = 15 5 15 15 15 15 15
4) Elisabeth buys 4/6 lbs of grapes and 5/7 lbs of oranges. Does she buy more grapes or more oranges? How many lbs of fruit does she buy in total?
4 5 28 30 5 4 , → , ⇒ > She buys more oranges 6 7 42 42 7 6 4 5 28 30 58 29 29 + = + = = She buys in total lbs of fruit 6 7 42 42 42 21 21
Maths 1º ESO 5)A teacher has marked 2/7 of his exams with a red marker and 1/4 with a blue one. If he still has 52 exams to mark, how many exams did he start with?
2 1 8 7 15 + = + = 7 4 28 28 28
15 13 = and they are 52 28 28 52 ÷ 13 = 4 → 4 × 28 = 112 He started with 112 exams
He still has to mark 1 −
6) In a 5600 m2 farm, they grow maize, onions and potatoes. They use three eighths of the farm for growing maize and two fifths of the remainder for growing onions, how many square metres do they use for growing potatoes?
3 for growing potatoes (see the picture) 8
3 3 × 5600 of 5600 = = 2100 m2 for growing potatoes 8 8