81+9+91用乘法的运算定律计算
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/17 22:51:14
![81+9+91用乘法的运算定律计算](/uploads/image/z/68127-15-7.jpg?t=81%2B9%2B91%E7%94%A8%E4%B9%98%E6%B3%95%E7%9A%84%E8%BF%90%E7%AE%97%E5%AE%9A%E5%BE%8B%E8%AE%A1%E7%AE%97)
81+9+91用乘法的运算定律计算
81+9+91用乘法的运算定律计算
81+9+91用乘法的运算定律计算
81+9+91=9X9+9+91
=(9X10)+90+1
=90+90+1
=90X2+1
=180+1
=181
81+9+91
=9X9+9+10X10-9
=9X10+10X10-9
=19X10-9
=190-9
=181
81+9+91
=9X9+9+10X10-9
=9X10+10X10-9
=19X10-9
=190-9
=181
解: 81+9+91=9X9+9+91 =(9X10)+90+1 =90+90+1 =90X2+1 =180+1 =181