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用简便方法计算.245+362+55+138356-178-12225×6×4;6.23-1.87-2.13+3.77.

题目详情
用简便方法计算.
245+362+55+138
356-178-122
25×6×4;                            
6.23-1.87-2.13+3.77.
▼优质解答
答案和解析
(1)245+362+55+138
=(245+55)+(362+138)
=300+500
=800;

(2)356-178-122
=356-(178+122)
=356-300
=56;

(3)25×6×4
=25×4×6
=100×6
=600;

(4)6.23-1.87-2.13+3.77
=(6.23+3.77)-(1.87+2.13)
=10-4
=6.