①30.1-16.4-3.6
②25.5+7.91+2.09+4.5
③101×53-53
④235-(456+304)÷4
⑤720÷(89-5×16)
⑥860×[137-(162-33)]
25×100= 70×20= 360÷3= 230×3=
11×600= 45+56= 20x340= 600÷50=
9×800= 84÷7= 7×110= 210÷6÷5=
50×800= 17×40= 420÷70= 25×4+20=
①7.45+6.28+3.72
②48×101
③76×99+76
④54.2-13.4-6.36
⑤(64-49)×25+40
⑥17×[325÷(19+6)]
①879-(179+97)
②629-128-72
③9+99+999+9999
④76×99+76
⑤373×36-36×73
⑥99×56
树高/m
1
2
3
4
5
影长/m
0.8
1.6
2.4
3.2