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简便计算25.25+34.72+74.75+65.282-0.55-0.450.99+1.99+2.99+3.9914.02-(3.02-1.29)

题目详情
简便计算
25.25+34.72+74.75+65.28
2-0.55-0.45
0.99+1.99+2.99+3.99
14.02-(3.02-1.29)
▼优质解答
答案和解析
(1)25.25+34.72+74.75+65.28
=(25.25+74.45)+(34.72+65.28)
=100+100
=200

(2)2-0.55-0.45
=2-(0.55+0.45)
=2-1
=1

(3)0.99+1.99+2.99+3.99
=(1-0.01)+(2-0.01)+(3-0.01)+(4-0.01)
=(1+2+3+4)-(0.01+0.01+0.01+0.01)
=10-0.04
=9.96

(4)14.02-(3.02-1.29)
=14.02-3.02+1.29
=11+1.29
=12.29