1
2 -0.25=0.25,
0.5+
2
5 =0.9,
3÷
6
5 =2.5,
5
7 ×
4
15 =
4
21 ,
1.25×0.16×8=1.6,
0.9+99×0.9=99, 400÷25÷8=4, 8×12.5%=1, (0.16+0.8)÷8=0.03,
3
4 ÷3+3÷
3
4 =4
1
4 .
1
2 -0.25=0.25,
0.5+
2
5 =0.9,
3÷
6
5 =2.5,
5
7 ×
4
15 =
4
21 ,
1.25×0.16×8=1.6,
0.9+99×0.9=99, 400÷25÷8=4, 8×12.5%=1, (0.16+0.8)÷8=0.03,
3
4 ÷3+3÷
3
4 =4
1
4 .