Dạng 2: Tính nhanh:

Đáp án:

 `a)`

`85.12,7+5,3.127`

`=85.12,7+5,3.10.12,7`

`=85.12,7+53.12,7`

`=12,7.(85+53)`

`=12,7.138`

`=1752,6`

`b)`

`52.143-52.39-8.26`

`=52.(143-39)-8.26`

`=52.104-8.26`

`=52.4.26-8.26`

`=26.(208-8)`

`=26.200`

`=5200`

`c)`

`15.91,5+150.0,85`

 `=15.91,5+15.10.0,85`

`=15.91,5+15.8,5`

`=15.(91,5+8,5)`

`=15.100`

`=1500`

`d)`

`37,5.6,5-6,6.7,5+3,5.37,5`

`=37,5.(6,5+3,5)-6,6.7,5`

`=37,5.10-6,6.7,5`

`=375-6,6.7,5`

`=50.7,5-6,6.7,5`

`=7,5.(50-6,6)`

`=7,5.43,4`

`=325,5`