1

2.(78.5%) (1.57) times

3、

(1(25+30) × 20 ÷ 2 = 550 (m) 550 ÷ 0.4 =1375 (tree).

(2) 1.30m = 130(DM)+030≈30≈4≈90≈3 = 3。

﹙3﹚60×35=2 100﹙㎝﹚2 100÷50=42﹙㎝﹚﹙42+64﹚×2=204﹙㎝﹚=2.04﹙m﹚

﹙4﹚3×4÷5=2.4﹙㎝﹚ 24×9÷2= 10.8﹙㎝﹚

Page 56

1、C A B B

2, the first above, the second front, the third side.

3、﹙ 1﹚ 20dm？

(2) 1 3 1

4. Draw two circles with a radius of 1 cm.

Is the surface area 18.84㎝? Volume 6.28㎝?

Page 57

1、﹙ 1﹚ 120L

﹙2﹚324㎝? 2 16㎝?

﹙3﹚ 72㎝? 48㎝?

2. The volume is 20× 16× 7 = 2240 ㎝? (Height: 2240 ~16×10 ~ =14 ~)

3. The volume is 28.26× 2×1/3 =18.84m? The bottom area is 3. 14×2? = 12.56﹙m？ (Height18.84 ÷12.56 =1.5 〃 m)

4、8dm = 80㎝4dm = 40㎝80×40×5= 16000﹙㎝？ ﹚ 16000÷4=4000﹙㎝? ﹚

Handmade, hope to adopt, thank you.