175+25=200, 1000-700=300, 36÷4=9, 13×10=130,
2.5×12=30, 0.7+0.03=0.73, 0×3.7÷1.2=0,
5
9 +
2
9 =
7
9 ,
2
4
7 -
3
7 =2
1
7 ,
1
4 +0.5=0.75, 39×21≈800, 198÷19≈10.
175+25=200, 1000-700=300, 36÷4=9, 13×10=130,
2.5×12=30, 0.7+0.03=0.73, 0×3.7÷1.2=0,
5
9 +
2
9 =
7
9 ,
2
4
7 -
3
7 =2
1
7 ,
1
4 +0.5=0.75, 39×21≈800, 198÷19≈10.