1. 直接写出得数。
1−0.03=
6.68+0.6=
12.2+0.7=
5.2+4.81=
2÷100=
0.23+0.8=
1.6+0.9=
3.65+5=
3.5−0.85=
5−0.5=
14.15+0.35=
11÷5=
1÷1000=
24+2.6=
150×6=

1. 0.97 7.28 12.9 10.01 0.02 1.03 2.5 8.65 2.65 4.5 14.5 2.2 0.001 26.6 900

2. 列竖式计算。
2.76+9.54=
21.1−4.98=
25−6.37=

2. 12.3 16.12 18.63

3. 递等式计算。(能简算的要简算)
$8.57+1.85-1.57$
$109-11.3-4.3-3.4$
$4.6+28.25+5.4+2.75$
$8.19-5.9+12.81-4.1$
$42.5-(10.08-4.23)$
$19.7+2.36-3.89$

3. 8.57+1.85−1.57=8.57−1.57+1.85=7+1.85=8.85
109−11.3−4.3−3.4=109−(11.3+4.3+3.4)=109−19=90
4.6+28.25+5.4+2.75=(4.6+5.4)+(28.25+2.75)=10+31=41
8.19−5.9+12.81−4.1=(8.19+12.81)−(5.9+4.1)=21−10=11
42.5−(10.08−4.23)=42.5−5.85=36.65
19.7+2.36−3.89=22.06−3.89=18.17