49*12+202 1.5-3.75/25的简便计算
问题描述:
49*12+202 1.5-3.75/25的简便计算
答
49*12+202
=(50-1)*12+202
=50*12-12+202
=600+190
=790
1.5-3.75/25
=1.5-(5-1.25)/25
=1.5-5/25+1.25/25
=1.5-0.2+0.05
=1.35