2. Li Ming encircles a triangle with a 1m long iron wire. Have you ever measured that one side of a triangle is 1/4, the other side is 3/8m, and how long is the third side? It is a 1- 1/4-3/8.

=8/8-2/8-3/8

= 3/8m

This triangle is an isosceles triangle.

3.？ Class 5 (1) students spent 10 hours visiting the old revolutionary base areas, of which15 was spent on the road, 3/ 10 was spent on lunch and rest, and the rest was sightseeing time. What's the percentage of sightseeing time?

1- 1/5-3/ 10

= 10/ 10-2/ 10-3/ 10

= 1/2

4. The land area of China is divided by altitude as follows (unit: meter).

Below 500 500~ 1000? 1000 ~ more than 2000? More than 2000 ~5000? More than 5000

Low hills and plains? Low mountains and hills, high mountains? Alpine high plains? Alpine region

4/25? 19/ 1007/25? 9/50 19/ 100

(1) Altitude 100m and 100m? What is the following area * * *?

(2) The area above100m is occupied by * * * *.

How much/how much? (3) What questions can I ask? Answer your question.

5. Fill in the appropriate operation symbols in ○.

2/3○3/ 14=3/ 14+2/3? 1/2+4/7+3/7= 1/2+(4/7○3/7)

6.

draw