题目内容
你能用不同的方法对48×15进行简算吗?
方法一:
方法一:
48×15,
=12×4×15,
=12×(4×15),
=12×60,
=720
=12×4×15,
=12×(4×15),
=12×60,
=720
48×15,
=12×4×15,
=12×(4×15),
=12×60,
=720
;方法二:=12×4×15,
=12×(4×15),
=12×60,
=720
48×15,
=(50-2)×15,
=50×15-2×15,
=750-30,
=720
=(50-2)×15,
=50×15-2×15,
=750-30,
=720
48×15,
=(50-2)×15,
=50×15-2×15,
=750-30,
=720
.=(50-2)×15,
=50×15-2×15,
=750-30,
=720
分析:方法一:先把48×15写成12×4×15,再运用乘法结合律进行计算;方法二:先把48×15写成(50-2)×15,再根据乘法分配律进行简算.
解答:解:方法一:
48×15,
=12×4×15,
=12×(4×15),
=12×60,
=720;
方法二:
48×15,
=(50-2)×15,
=50×15-2×15,
=750-30,
=720.
48×15,
=12×4×15,
=12×(4×15),
=12×60,
=720;
方法二:
48×15,
=(50-2)×15,
=50×15-2×15,
=750-30,
=720.
点评:此题主要考查学生能根据算式中数据特点,灵活选择不同方法及运算定律进行简算的能力.
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