14.口算:
3.6+4.4= | 10-5.2= | 3.4×0.2= | 7.8÷6= |
1÷4= | 7.5÷0.3= | 9.8-8= | 0÷27.9= |
6.5×0.2= | 0.1×0.5= | 13.2+6.8= | 0.15÷15= |
2+3.8= | 9-4.5= | 0.42×3= | 11+0.92= |
4÷5= | 1.8÷0.03= | 75÷2.5= | 0×25.4= |
0.125×8= | 7.24-2.4= | 17.2÷17.2= | 0.99×0.1= |
10.脱式计算.
53×102+371; | 175+383+25; | 125×4+168÷4 |
(380-300)÷5+184; | (377-360)×306÷3; | 1163+(214×15-827); |
74×(201-37)-356; | (147-305÷5)×4. |
8.估算.
180×49≈ | 203×93≈ | 57×298≈ |
917×50≈ | 61×207≈ | 139×48≈ |
7.直接写得数.
72×60= | 250×40= | 73×20= | 75×40= |
81×50= | 15×4= | 43×200= | 75×500= |
700×40= | 11×600= | 20×140= | 600×400= |
6.已知A×B=320,如果A乘以2,B除以2,那么现在的积是( )
0 160459 160467 160473 160477 160483 160485 160489 160495 160497 160503 160509 160513 160515 160519 160525 160527 160533 160537 160539 160543 160545 160549 160551 160553 160554 160555 160557 160558 160559 160561 160563 160567 160569 160573 160575 160579 160585 160587 160593 160597 160599 160603 160609 160615 160617 160623 160627 160629 160635 160639 160645 160653 199269
A. | 40 | B. | 320 | C. | 160 |