Question

用简便方法计算：4×0.27×25 3.8×99＋3.8 （8＋4/9）÷4 2/5＋3/7＋3/5＋4/7

Answer 1

4×0.27×25

=0.27×4×25

=0.27×100

=27;

3.8×99＋3.8

=3.8×(1+99)

=3.8×100

=380;

（8＋4/9）÷4

=2+1/9

=19/9;

2/5＋3/7＋3/5＋4/7

=(2/5+3/5)+(3/7+4/7)

=1+1

=2;