1.直接写出得数。
0.615×100=
3.2+9.18=
5a+4a=
0.615÷100=
73−1.7=
5a×4a=
5.14−2.7=
2.09×100=
12x−2.5x=
2.08×0.5=
2.05×4=
y÷y=
0.5×0.5=
4−1.67=
4m+0=

1. 61.5
1. 12.38
1. 9a
1. 0.00615
1. 71.3
1. 20a²
1. 2.44
1. 209
1. 9.5x
1. 1.04
1. 8.2
1. 1
1. 0.25
1. 2.33
1. 4m

2. 算式接龙。

4.36 +1.4 ×3 +2.72
↓ ×20

← ÷1000
← ×8
← ×2.5

3.递等式计算。(能简算的要简算)
$37.5+4.9-7.5+15.1$
$2.57×5.78+4.22×2.57$
$8.6×10.1$
$0.625×8.3-6.25×0.03$

3. $37.5+4.9-7.5+15.1=(37.5-7.5)+(4.9+15.1)=30+20=50$
3. $2.57×5.78+4.22×2.57=2.57×(5.78+4.22)=2.57×10=25.7$
3. $8.6×10.1=8.6×(10+0.1)=8.6×10+8.6×0.1=86+0.86=86.86$
3. $0.625×8.3-6.25×0.03=0.625×8.3-0.625×0.3=0.625×(8.3-0.3)=0.625×8=5$