Odpowiedź :
4,2 + 1/4 = 4 2/10 + 1/4 = 4 8/40 + 10/40 = 4 18/40 = 4 9/20
2,35 - 3/4 = 2 35/100 - 75/100 = 1 135/100 - 75/100 = 1 60/100 = 1 3/5
12,2 x 1/4 = 12 2/10 x 1/4 = 12 1/5 x 1/4 = 61/5 x 1/4 = 61/20 = 3 1/20
1,3 : 5 1/5 = 1 3/10 : 5 1/5 = 13/10 : 26/5 = 13/10 x 5/26 = 1/4