一、口算。
6.2÷2=
6.1×2=
123-103=
9.6t÷6=
1.45×100=
0.64÷4=
505×20=
13.2÷6=
0.02×50=
1.14×8=
3.3+1.8=
66÷33=
10.3×3=
2.5-1.9=
336÷6=
0.48+0.17=
0.81×7=
3s-1.03s=
36÷8=
1.18÷2=
a×a=
78+120=
640÷10=
87×20=
1.46-0.96=
0.69÷23=
0.1+1.09=
0.036×10=
35.2÷1000=
0.7×41=

6.2÷2=3.1
6.1×2=12.2
123-103=20
9.6t÷6=1.6t
1.45×100=145
0.64÷4=0.16
505×20=10100
13.2÷6=2.2
0.02×50=1
1.14×8=9.12
3.3+1.8=5.1
66÷33=2
10.3×3=30.9
2.5-1.9=0.6
336÷6=56
0.48+0.17=0.65
0.81×7=5.67
3s-1.03s=1.97s
36÷8=4.5
1.18÷2=0.59
a×a=a²
78+120=198
640÷10=64
87×20=1740
1.46-0.96=0.5
0.69÷23=0.03
0.1+1.09=1.19
0.036×10=0.36
35.2÷1000=0.0352
0.7×41=28.7

二、填一填。
1. $3 + y + 5 = □ + □ + y$
2. $4.5x + 5.5x = (□ + □) × □$
3. $a - b - c = □ - (□ + □)$
4. $12.5 × a × □ = □ × (12.5 × 8)$
5. $$$ + b = □ + 5.6$
6. $22 × x + y × □ = (□ + □) × 22$

1. 3 5
2. 4.5 5.5 x
3. a b c
4. 8 a
5. 5.6 b
6. 22 x y