Question

2.79×99+2.1简便计算？

Answer 1

这类简便算法可以叫做“凑整简便法”
意思就是把接近整数的数凑成整数的形式进行计算。比如把99凑成100-1，把18凑成20-2，把7.9凑成8.0-0.1
所以这道题的计算方式是把99凑成100-1的形式
原式=2.79×(100-1)+2.1
=2.79×100-2.79×1+2.1
=279-2.79+2.1
=279-(2.79-2.1)
=279-0.69
=278.31
满意望采纳，谢谢。

Answer 2

2.79×99+2.1
=2.79×(100-1)+2.1
=2.79×100-2.79+2.1
=279-0.69
=278.31

Answer 3

解:

简便计算

2.79×99+2.1

=2.79×（100-1）+2.1

=2.79×100-2.79+2.1

=279-（3-0.21）+2.1

=279-3+0.21+2.1

=276.21+2.1

=278.31

Answer 4

这类简便算法可以叫做“凑整简便法”意思就是把接近整数的数凑成整数的形式进行计算。比如把99凑成100-1，把18凑成20-2，把7.9凑成8.0-0.1所以这道题的计算方式是把99凑成100-1的形式原式=2.79×(100-1)+2.1=2.79×100-2.79×1+2.1=279-2.79+2.1=279-(2.79-2.1)=279-0.69=278.31满意望采纳，谢谢。

Answer 5

2.79×99+2.1简便计算，可以用2.79x(100-1)+2.1=2.79x100-2.29x1=279-2.79+2.1=278.31