1.9+19.9+199.9+1999.9怎样用简便方法计算

2024-11-21 20:32:05
推荐回答(5个)
回答1:

1.9+19.9+199.9+1999.9
=(2-0.1)+(20-0.1)+(200-0.1)+(2000-0.1)
=(2+20+200+2000)-0.1*4
=2222-0.4
=2221.6

回答2:

1.9+19.9+199.9+1999.9=2-0.1+20-0.1+200-0.1+2000-0.1=2222-0.4=2221.6

回答3:

1.9+19.9+199.9+1999.9
=(2-0.1)+(20-0.1)+(200-0.1)+(2000-0.1)
=(2+20+200+2000)-0.1×4
=贺源备2222-0.4
=禅毁裂卖2221.6

回答4:

1.9+19.9+199.9+1999.9+0.4-0.4
=2+20+200+2000-0.4
=2222-0.4
=2221.6

回答5:

2+20+200+2000=2222-0.4=2221.6