问题 解答题

用简便方法计算.

415-176-24

8.29+3.7+0.71+6.3

428×78+572×78.

答案

(1)415-176-24

=415-(176+24)

=415-200

=215;

(2)8.29+3.7+0.71+6.3

=(8.29+0.71)+(3.7+6.3)

=9+10

=19;

(3)428×78+572×78

=(428+572)×78

=1000×78

=78000.

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