3 3/4+1 1/2
2 5/6-1 5/12
4 -1 2/3
3 2/7-6/7
1 1/3*4
3 1/4*2/5
2 1/4:3
20:2 1/2

3 3/4+1 1/2=3 3/4+1 2/4=4 5/4==5 1/42 5/6-1 5/12=2 10/12-1 5/12=1 5/124-1 2/3=3 3/3-1 2/3=2 1/33 2/7-6/7=2 9/7-6/7=2 3/71 1/3×4=4/3×4=16/3=5 1/33 1/4×2/5=13/4×2/5=13/10=1 3/102 1/4÷3=9/4÷3=9/4×1/3=3/420÷2 1/2=20÷5/2=20×2/5=8

3 3/4 + 1 1/2 = 3 3/4 + 1 2/4 = 4 5/4 = 5 1/42 5/6 - 1 5/12 = 2 10/12 - 1 5/12 = 1 5/124 - 1 2/3 = 3 3/3 - 1 2/3 = 2 1/33 2/7 - 6/7 = 2 9/7 - 6/7 = 2 3/71 1/3 * 4 = 4/3 * 4 = 16/3 = 5 1/33 1/4 * 2/5 = 13/4 * 2/5 = 26/20 = 1 6/20 = 1 3/102 1/4 : 3 = 9/4 : 3 = 9/4 * 1/3 = (3*1)/(4*1) = 3/420 : 2 1/2 = 20 : 5/2 = 20 * 2/5 = (4*2)/1 = 8