Question

有几道奥数 简算题 题请想大家解答一下

请大家帮帮忙
第一题 3 3/5×25 2/5＋37.9×6 2/5
（3 3/5也就是三又五分之三）
第二题 6.8×16.8＋19.3×3.2
注意：一定要简算

Answer 1

3.6X25.4+37.9x6.4
=3.6X25.4+(25.4+12.5)X6.4
=(3.6+6.4)X25.4+12.5X6.4
=254+80
=334

6.8X16.8+(16.8+2.5)X3.2
=16.8X(6.8+3.2)+2.5x3.2
=168+8
=176

Answer 2

(3+3/5)×(25+2/5)＋37.9×(6+2/5)
=18/5*127/5+379/10*32/5
=18/5*127/5+379/5*16/5
=18/5*127/5+(127*3-2)/5*16/5
=18/5*127/5+127*3*16/5-2/5*16/5
=18/5*127/5+127*48/5-2/5*16/5
=(18/5+48/5)*127/5-2/5*16/5
=66*127/25-32/25
=8382/25-32/25
=335+7/25-32/25
=335-1
=334

6.8×16.8＋19.3×3.2
=(10-3.2)*16.8+19.3*3.2
=10*16.8-3.2*16.8+19.3*3.2
=168+3.2*(19.3-16.8)
=168+2.5*3.2
=168+8
=176

Answer 3

3.6X25.4+37.9x6.4
=3.6X25.4+(25.4+12.5)X6.4
=(3.6+6.4)X25.4+12.5X6.4
=254+80
=334
6.8×16.8＋19.3×3.2
=(10-3.2)*16.8+19.3*3.2
=10*16.8-3.2*16.8+19.3*3.2
=168+3.2*(19.3-16.8)
=168+2.5*3.2
=168+8
=176