| 86×137+86 | 90.02-20.06-19.94 | 71×99. |
=86×(137+1),
=86×138,
=11868;
(2)90.02-20.06-19.94,
=90.02-(20.06+19.94),
=90.02-40,
=50.02;
(3)71×99,
=71×(100-1),
=71×100-71×1,
=7100-71,
=7029.
编辑:chaxungu时间:2026-04-27 13:18:27分类:小学数学题库
| 86×137+86 | 90.02-20.06-19.94 | 71×99. |