Odpowiedź:
a) 3/4 + 1/2 = 3/4 + 2/4 = 5/4 = 4/4 + 1/4 = 1 + 1/4 = 1 1/4 (jedna cała i 1/4)
b) 3/10 + 5/10 = 8/10
c) 4/7 - 1/14 = 8/14 - 1/14 = 7/14 = 1/2
d) 7/12 + 3/4 = 7/12 + 9/12 = 16/12 = 4/3 = 3/3 + 1/3 = 1 + 1/3 = 1 1/3
(1 cała i 1/3)
e) 2/5 + 7/15 = 6/15 + 7/15 = 13/15
f) 3/8 + 3/4 = 3/8 + 6/8 = 9/8
g) 2/3 - 5/9 = 6/9 - 5/9 = 1/9
h) 7/5 - 7/20 = 28/20 - 7/20 = 21/20 = 20/20 + 1/20 = 1 + 1/20 = 1 1/20
(1 cała i 1/20)
i) 4/5 - 3/20 = 16/20 - 3/20 = 13/20
Szczegółowe wyjaśnienie:
a) 3/4 + 1/2 = 3/4 + 2/4 = 5/4 = 4/4 + 1/4 = 1 + 1/4 = 1 1/4 (jedna cała i 1/4)
b) 3/10 + 5/10 = 8/10
c) 4/7 - 1/14 = 8/14 - 1/14 = 7/14 = 1/2
d) 7/12 + 3/4 = 7/12 + 9/12 = 16/12 = 4/3 = 3/3 + 1/3 = 1 + 1/3 = 1 1/3
(1 cała i 1/3)
e) 2/5 + 7/15 = 6/15 + 7/15 = 13/15
f) 3/8 + 3/4 = 3/8 + 6/8 = 9/8
g) 2/3 - 5/9 = 6/9 - 5/9 = 1/9
h) 7/5 - 7/20 = 28/20 - 7/20 = 21/20 = 20/20 + 1/20 = 1 + 1/20 = 1 1/20
(1 cała i 1/20)
i) 4/5 - 3/20 = 16/20 - 3/20 = 13/20
