Question

急！！！奥数题

填空：【（32÷5+2.4）×16+9.2】÷9.6=
简便计算：
（1）1.1+1.91+1.991+...+1.99...991 （1.99...991一共有100个9）
（2）3.6×42.3×3.75-12.5×0.423×28
（3）3.6×31.4+43.9×6.4
（4）18×222.2-666.6
（5）19.58×66+22×91.26
（6）0.888×12.5×0.9+0.01

Answer 1

计算：【（32÷5+2.4）×16+9.2】÷9.6
=[8.8*16+9.2]/9.6
=8.8*16/9.6+23/24
=11*16/12+23/24
=176/12+23/24
=375/24
=125/8
简便计算：
（2）3.6×42.3×3.75-12.5×0.423×28
=42.3*(3.6*3.75-0.125*28)
=42.3*(13.5-3.5）
=423
（3）3.6×31.4+43.9×6.4
=3.6*31.4+43.9*（10-3.6）
=3.6*31.4+439-43.9*3.6
=439-3.6*(43.9-31.4)
=439-3.6*12.5
=439-0.45*100
=439-45
=394
（4）18×222.2-666.6
=222.2*（18-3）
=222.2*15
=3333
（5）19.58×66+22×91.26
=22*（19.58*3+91.26）
=22*150
=3300
（6）0.888×12.5×0.9+0.01
=0.8*12.5*1.11*0.9+0.01
=11.1*0.9+0.01
=9.99+0.01
=10