9.6+29.8+169.9+399.5用速算或巧算等于多少

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9.6+29.8+169.9+399.5用速算或巧算等于多少
9.6+29.8+169.9+399.5用速算或巧算等于多少

9.6+29.8+169.9+399.5用速算或巧算等于多少
608.8

610-1.2=608.8

原式=(10-0.4)+(30-0.2)+(170-0.1)+(400-0.5)
=10+30+170+400-(0.4+0.2+0.1+0.5)
=610-1.2
=608.8

9.6+29.8+169.9+399.5
=10+30+170+400-1.2
=610-1.2
=608.8