四、解决问题
★信息窗2-3
建议用时:7分钟
实际用时:分钟
370+40+60 =
100+36+44 =
45+55 =
300+600-700 =
600-300+400 =
55÷9 =
400+600+700 =
29+40+30 =
28÷8 =
87-49+38 =
770-30+60 =
4×8 =
17+42+36 =
890-40-20 =
6×9 =
64-8+42 =
180-70+40 =
27+80 =
65-35+40 =
100+400+60 =
156-90 =
50+60-40 =
1000-600+200 =
62÷8 =
270+400+20 =
300+600+100 =
42÷7 =
820+40+60 =
500+60+40 =
37-17 =
73-43+6 =
300+1000-600 =
8×8 =
500+400+30 =
50+400+300 =
71÷8 =
28+100-40 =
2000+3000+600 =
125-90 =
127+30+10 =
1000-300+200 =
16÷8 =
200+600-300 =
4000-3000+600 =
9×2 =

$370+40+60=470$
$100+36+44=180$
$45+55=100$
$300+600-700=200$
$600-300+400=700$
$55÷9=6······1$
$400+600+700=1700$
$29+40+30=99$
$28÷8=3······4$
$87-49+38=76$
$770-30+60=800$
$4×8=32$
$17+42+36=95$
$890-40-20=830$
$6×9=54$
$64-8+42=98$
$180-70+40=150$
$27+80=107$
$65-35+40=70$
$100+400+60=560$
$156-90=66$
$50+60-40=70$
$1000-600+200=600$
$62÷8=7······6$
$270+400+20=690$
$300+600+100=1000$
$42÷7=6$
$820+40+60=920$
$500+60+40=600$
$37-17=20$
$73-43+6=36$
$300+1000-600=700$
$8×8=64$
$500+400+30=930$
$50+400+300=750$
$71÷8=8······7$
$28+100-40=88$
$2000+3000+600=5600$
$125-90=35$
$127+30+10=167$
$1000-300+200=900$
$16÷8=2$
$200+600-300=500$
$4000-3000+600=1600$
$9×2=18$

拓展园地
7个连续数的和是56，其中第4个数是多少？

8