1, slightly 2.3. 14 times (47. 1÷3. 14÷2)? +47. 1×35×20=36502.5(cm？ 0

3、8.5×4 ×3= 102(dm？ )

3. 14×(8÷2)? ×5=25 1.2(cm？ )

3 molecules 1×3. 14 times (15÷2)? ×8=47 1(cm？ )

4、3. 14×( 12÷2)? ×9—3. 14×(2÷2)? ×9× 12=678.24(cm？ )≈678(cm？ )

5.2cm = 0.02m3+0× 28.26× 2.5÷10÷ 0.02 =117.75 (m)

6、3. 14×(4÷2)? ×4=50.24(dm？ )

Exercise 6: 1, (from left to right) cannot form a proportion; Can form a proportion; Column: 30: 2 =120: 8; Cannot form proportion' can form proportion, 100: 5 = 200:: 10.

2. (1) can form a ratio:

4.5 = 12: 15 4: 12 = 5: 15: 5 = 12: 4 15: 12 = 5: 4.

(2 ") can't form a proportion.

(3) can't form a proportion

(4) can form a proportion

1: 1 = 1: 6, 1: 1 = 1: 1.

65438 of 6+0: 65438 of 3+0 = 65438 of 4+0: 65438 of 26+0: 65438 of 4+0 = 65438 of 3+0: 65438 of 2+0 (the answer is not unique).

3,5:110: 25:1=10: 2 (the answer is not unique)

4.( 1) can form a ratio, namely 12: 16=3:4.

(2) Internal items are 16 and 3, and external items are 12 and 4.

5.( 1) cannot form a proportion.

(2) the proportion of energy composition

(3) can be proportional

(4) can't form a proportion

654/45 times 60=72 (times)

7. (Horizontal) x = 65438+1x =1.6x = 3x = 2x = 36x = 8.

8. Solution: Let its actual length be xm.

24.92:x= 1:24

x=598.08

Solution: Let ............... do ycm.

11.76m =1176cm

y: 1 176= 1:24

y=49

9. Solution: .............. xcm

19.6:x= 1: 10

x= 196

196cm =1.96m.

10, omitted

1 1, omitted.

12, omitted

13, (1) 10 4 (the answer is not unique)

(2)0.7 9 (the answer is not unique)

I suggest buying the Complete Solution for Primary School Textbooks. The sixth grade math (the second volume) has the answer. It seems that I answered from the inside.

I was exhausted from playing. Give me satisfaction (O(∩_∩)O Thank you)