3.合理计算下列各题
637÷13×(467-428) | 251-17.5÷10+90 | 12.3+4.8-5.3+18.2 |
72.44-43.8-15.6 | 14×72×125 | 139×127十139×74 |
2.直接写出得数
0.45+3.5= | 28÷i0= | 7.3-5.23= | 30-18.9= |
1.2×2×50= | 1.7+13.3= | 700÷25÷4= | 4.3-2.3+0.7= |
1.下面等式可以成立的是( )
A. | 38.5-l9.7=38.5-20-0.3 | B. | 477×178=477×200-22×477 | ||
C. | 17.8-(5.8+4.9)=17.8-5.8+4.9 | D. | 364×42×49=(364×40)×(2×49) |
20.将一根粗细均匀的木条锯成3段需要6分钟,如果锯成8段,需要( )分钟.
A. | 16 | B. | 24 | C. | 14 | D. | 21 |
19.将0.9缩小到它的$\frac{1}{10}$,结果比原数减少了( )
0 160876 160884 160890 160894 160900 160902 160906 160912 160914 160920 160926 160930 160932 160936 160942 160944 160950 160954 160956 160960 160962 160966 160968 160970 160971 160972 160974 160975 160976 160978 160980 160984 160986 160990 160992 160996 161002 161004 161010 161014 161016 161020 161026 161032 161034 161040 161044 161046 161052 161056 161062 161070 199269
A. | 0.O9 | B. | O.01 | C. | 9.1 | D. | 0.81 |