1, two-headed planting: number of plants = total length ÷ spacing+1, total length = spacing × (number of plants-1), spacing = total length ÷ (tree-1).

2. Only plant one head: tree = full length ÷ spacing, full length = spacing × tree, spacing = full length ÷ tree.

3. No planting at both ends: tree = total length ÷ spacing-1, total length = spacing × (number of plants+1), spacing = total length ÷ (number of plants+1).

If the length is n meters, plant a tree every m meters.

5. Planting trees at both ends requires n÷m+ 1 tree.

6. It takes n \m trees to plant trees at one end and not at the other.

7. No trees are planted at both ends, and n \m- 1 tree is needed.

8, circular tree planting, tree height n÷ m. ..

Application of planting trees in the first volume of the fifth grade

1. Saw a steel pipe into small pieces for 28 minutes. It takes 4 minutes to saw each part. How many sections has this steel pipe been sawed into?

2. There is a piece of wood that needs to be sawed into four sections. It takes 5 minutes to cut each part. How many minutes will it take to saw it all?

It took 15 minutes to saw a piece of wood into 2-meter-long sections. It is known that it takes 3 minutes to saw the next section. How long is this wood?

4. Xiaoming climbs the stairs, taking 12 steps every time, and the first step takes 2 seconds. How long does it take Xiaoming to walk from the first floor to the fourth floor?

5. There is a building with floors 17, and there are steps 17 between two adjacent floors. Someone walks from the first floor to the eleventh floor. How many steps does a * * * have to climb?