一、口算。
3.14×40 =
7.25 + 2.75 =
2.25 ÷ 0.5 =
188.4 ÷ 3.14 =
4.4 × 0.4 =
0.97 - 0.45 =
2.198 ÷ 3.14 =
0.125 × 16 =
4.8 ÷ 0.8 =
3.14 × 0.8 =
777 - 65 =
5.7 + 3.3 =
$3.14 × 4^2 =$
2.35 + 76.5 =
7.2 ÷ 0.4 =
0.628 ÷ 3.14 =
0.34 × 0.5 =
0.67 + 0.33 =
3.768 ÷ 3.14 =
2.4 ÷ 12 =
700 ÷ 35 =
3.14 × 0.03 =
4.57 - 3.5 =
467 + 70 =
56.52 ÷ 3.14 =
460 × 4 =
3 × 1.06 =
2512 ÷ 3.14 =
0.39 + 0.64 =
8 ÷ 0.01 =

1. 3.14×40 = 125.6
2. 7.25 + 2.75 = 10
3. 2.25 ÷ 0.5 = 4.5
4. 188.4 ÷ 3.14 = 60
5. 4.4 × 0.4 = 1.76
6. 0.97 - 0.45 = 0.52
7. 2.198 ÷ 3.14 = 0.7
8. 0.125 × 16 = 2
9. 4.8 ÷ 0.8 = 6
10. 3.14 × 0.8 = 2.512
11. 777 - 65 = 712
12. 5.7 + 3.3 = 9
13. $3.14 × 4^2 = 50.24$
14. 2.35 + 76.5 = 78.85
15. 7.2 ÷ 0.4 = 18
16. 0.628 ÷ 3.14 = 0.2
17. 0.34 × 0.5 = 0.17
18. 0.67 + 0.33 = 1
19. 3.768 ÷ 3.14 = 1.2
20. 2.4 ÷ 12 = 0.2
21. 700 ÷ 35 = 20
22. 3.14 × 0.03 = 0.0942
23. 4.57 - 3.5 = 1.07
24. 467 + 70 = 537
25. 56.52 ÷ 3.14 = 18
26. 460 × 4 = 1840
27. 3 × 1.06 = 3.18
28. 2512 ÷ 3.14 = 800
29. 0.39 + 0.64 = 1.03
30. 8 ÷ 0.01 = 800

二、填表。

1. 半径4cm，直径12.56cm，周长12.56cm²
2. 半径3dm，直径18.84dm，周长28.26dm²
3. 半径40m，直径80m，周长5024m²
4. 半径6cm，直径12cm，周长37.68cm