31/4*4 10*5 2/5 3 5/16 * 1 3*5 1/3 4 1/2: 6 3/4 2 1/2*3 1/15 4/9 * 3 3/4 1 6/7 * 3 5/10 10: 3 1/3

3 1/4*4=13/4×4=13;
10*5 2/5= 10×27/5=2×27=54;
3 5/16 * 1=3_5/16;
3*5 1/3=3×16/3=16;
4 1/2: 6 3/4=9/2÷27/4=9/2×4/27=9×4/2×27=2/3;
2 1/2*3 1/15=5/2×46/15=5×46/2×15=23/3=7_2/3;
4/9 * 3 3/4=4/9×15/4= 4×15/9×4=5/3=1_2/3;
1 6/7 * 3 5/10=13/7×3_1/2= 13/7×7/2=13×7/7×2=13/2=6_1/2;
10:3 1/3=10÷10/3=10×3/10=3

31/4*4=31/4*4/1=124/4=31
10*5 2/5=10*27/5= 270/5=54
3 5/16*1=48/16*2=3
3*5 1/3=3*16/3=48/3=16
4 1/2:6 3/4=9/2:27/4=9/2*4/27=36/54=2/3
2 1/2*3 1/15=5/2*45/15= 225/30=45/6
4/9*3 3/4=4/9*15/4=60/36 =5/3
16/7*3 5/10=16/7*35/10=560/70=8
10:3 1/3=10/1:10/3=10/1*3/10 =3