18.在一道减法算式中,被减数、减数与差的和是48,被减数是( )
| A. | 24 | B. | 12 | C. | 16 | D. | 18 |
17.三个数的平均数是2.8,如果再加上2,这四个数的平均数是( )
| A. | 2.8 | B. | 2.6 | C. | 2.7 | D. | 2.9 |
16.125×72的最佳简便算法是( )
0 140483 140491 140497 140501 140507 140509 140513 140519 140521 140527 140533 140537 140539 140543 140549 140551 140557 140561 140563 140567 140569 140573 140575 140577 140578 140579 140581 140582 140583 140585 140587 140591 140593 140597 140599 140603 140609 140611 140617 140621 140623 140627 140633 140639 140641 140647 140651 140653 140659 140663 140669 140677 199269
| A. | 124×4×18 | B. | 125×4×2×3×3 | C. | 125×8×9 | D. | 125×70+125×2 |