请教3道奥数题 简便计算

题目

请教3道奥数题 简便计算
1 444*25/(100/8.9)+1889*8.9
2 (112244-123.234）/（224488-246.468)
3 4.8*2.12+0.627*52+41.5*0.08
前面的1 2 3 是题号

答案

1.shizi=111*25*4*8.9/100+1889*8.9
=111*8.9+1889*8.9
=(111+1889)*8.9
=2000*8.9
=17800
2.(112244-123.234）/（224488-246.468)
=(112244-123.234)/(112244*2-123.234*2)
=(112244-123.234）/[(112244-123.234）*2]
=1/2=0.5
3.4.8*2.12+0.627*52+41.5*0.08
=48*0.212+52*0.627+8*0.415
=40*0.212+8*0.627+52*0.627
=40*0.212+60*0.627
=8.48+37.62
=46.1