四、解决问题
★信息窗1-2
建议用时:7分钟
实际用时:分钟
500+200+40 =
340+70+90 =
50+700+200 =
35+500-300 =
60+40+80 =
730+60+50 =
70+400+60 =
300+620+30 =
600+30+40 =
550-130+20 =
360+50+50 =
73-60+50 =
178-78-50 =
270+40+60 =
960-370+90 =
420-30+60 =
900-200+40 =
1000+4000-3000 =
960-80+80 =
1000-600+200 =
600+300-200 =
420+30+60 =
1000-600-300 =
700-300+200 =
2000-600+200 =
400+300-200 =
200+400-300 =
700-200+40 =
90-30+46 =
79-30+40 =
32÷5 =
16÷5 =
27÷3 =
42÷8 =
64÷8 =
38+49 =
146-70 =
23÷5 =
44÷9 =
279+60 =
100+20 =
320-50 =
127-20 =
89-69 =
78+56 =

$500+200+40=740$
$340+70+90=500$
$50+700+200=950$
$35+500-300=235$
$60+40+80=180$
$730+60+50=840$
$70+400+60=530$
$300+620+30=950$
$600+30+40=670$
$550-130+20=440$
$360+50+50=460$
$73-60+50=63$
$178-78-50=50$
$270+40+60=370$
$960-370+90=680$
$420-30+60=450$
$900-200+40=740$
$1000+4000-3000=2000$
$960-80+80=960$
$1000-600+200=600$
$600+300-200=700$
$420+30+60=510$
$1000-600-300=100$
$700-300+200=600$
$2000-600+200=1600$
$400+300-200=500$
$200+400-300=300$
$700-200+40=540$
$90-30+46=106$
$79-30+40=89$
$32÷5=6······2$
$16÷5=3······1$
$27÷3=9$
$42÷8=5······2$
$64÷8=8$
$38+49=87$
$146-70=76$
$23÷5=4······3$
$44÷9=4······8$
$279+60=339$
$100+20=120$
$320-50=270$
$127-20=107$
$89-69=20$
$78+56=134$

拓展园地
下面的图形从哪一点出发就可以一笔画成？（）

B或D