用简便方法计算 4538+3998 3.2×10.1 38×99+38 7/15÷5+8/15×1/5 1-0.225÷0.9-0.75 65×65/662.5×3.2×12.5
来源：学生作业帮助网 编辑：六六作业网 时间：2024/11/16 13:43:45
用简便方法计算4538+39983.2×10.138×99+387/15÷5+8/15×1/51-0.225÷0.9-0.7565×65/662.5×3.2×12.5用简便方法计算4538+39983
用简便方法计算 4538+3998 3.2×10.1 38×99+38 7/15÷5+8/15×1/5 1-0.225÷0.9-0.75 65×65/662.5×3.2×12.5
用简便方法计算 4538+3998 3.2×10.1 38×99+38 7/15÷5+8/15×1/5 1-0.225÷0.9-0.75 65×65/66
2.5×3.2×12.5
用简便方法计算 4538+3998 3.2×10.1 38×99+38 7/15÷5+8/15×1/5 1-0.225÷0.9-0.75 65×65/662.5×3.2×12.5
4538+3998
=4538+4000-2
=8538-2
=8536
3.2×10.1
=3.2×10+3.2×0.1
=32+0.32
=32.32
38×99+38
=38×（1+99）
=38×100
=3800
7/15÷5+8/15×1/5
=（7/15+8/15）×1/5
=1/5
1-0.225÷0.9-0.75
1-（0.25+0.75）
=1-1
=0
65×65/66
=65×（1-1/66）
=65-65/66
=64又1/66
2.5×3.2×12.5
=2.5×4×（0.8×12.5）
=10×10
=100