Question

4.巧算:+77*6.6+6.6*55+44*7.7？

Answer 1

77*6.6+6.6*55+44*7.7
=77*（6.6+4.4）+6.6*55 乘法交换律和分配律简便
=77*11+6.6*55
=11*（77+6.6*5）乘法分配律
=11*110
=1210

Answer 2

77×6.6+6.6×55+44×7.7

=11×11×4.2+11×11×3+11×11×2.8          ...............改写

=11×11×（4.2+3+2.8）

=121×10

=12100