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+4/74×0.27×253.8×99+3.8(8+4/9)÷42/5+3/7+3/5+4/7
问题描述:
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
4×0.27×25
3.8×99+3.8
(8+4/9)÷4
2/5+3/7+3/5+4/7
答
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;