2.9乘9.9加0.99简算
问题描述:
2.9乘9.9加0.99简算
答
2.9x9.9+0.99
=9.9x2.9+9.9x0.1
=9.9x(2.9+0.1)
=9.9x3
=(10-0.1)x3
=30-0.3
=29.7