Question

计算． 3.52÷2.5÷0.4	3.65×10.1	15÷（0.15×0.4）
1.97×99+1.97	4.8×7.8-78×0.42	12.5×34+25×33．

Answer 1

①3.52÷2.5÷0.4
=3.52÷（2.5×0.4）
=3.52÷1
=3.52；

②3.65×10.1
=3.65×10+3.65×0.1
=36.5+0.365
=36.865；


③15÷（0.15×0.4）
=15÷0.15÷0.4
=100÷0.4
=250；


④1.97×99+1.97
=1.97×（100+1）
=1.97×100
=197；

⑤4.8×7.8-78×0.42
=4.8×7.8-7.8×4.2
=（4.8-4.2）×7.8
=0.6×7.8
=4.68；

⑥12.5×34+25×33
=25×17+25×33
=25×（17+33）
=25×50
=1250．