问题
计算题
用简便方法计算下面各题 | ||||||
|
答案
687-298 | |
=687-300+2 | |
=389 | 348+(417+152) |
=(348+152)+417 | |
=917 | 867-457-243 |
=867-(457+243) | |
=167 | |
587-378+113 | |
=(587+113)-378 | |
=322 | 375+103 |
=375+100+3 |
=478
=(487-187)-37
=263
用简便方法计算下面各题 | ||||||
|
687-298 | |
=687-300+2 | |
=389 | 348+(417+152) |
=(348+152)+417 | |
=917 | 867-457-243 |
=867-(457+243) | |
=167 | |
587-378+113 | |
=(587+113)-378 | |
=322 | 375+103 |
=375+100+3 |
=478
=(487-187)-37
=263