1, experimental preparation.

Build a slope on the ground with 30 cm ~50 cm long wooden boards, so that the included angle between the slope and the ground is 30 (45, 60, etc.). ). Then gently place a cylindrical object (such as an adhesive tape ring) on the top of the slope, release your hand and let it roll down automatically. After the object stops rolling, measure the distance it rolls on the ground.

2. Record the experimental data.

3. Calculation and reasoning of experimental results.

Compare the average values obtained each time and tell your findings. Most students have this conjecture before the experiment: the steeper the slope (that is, the greater the angle between the slope and the ground), the farther the object will roll along the ground after reaching the bottom of the slope.

Is this conjecture correct? What is the relationship between the rolling distance of an object on the ground and the gradient of a slope? The textbook arranges students to correct the original conjecture and explore it through practical activities.

4. Matters needing attention in the experiment.

When students do experiments, they should be reminded to put cylindrical objects on the top of the slope, not to be high for a while and low for a while; To make the object roll down automatically, you can't push it by hand or block it by hand; It is necessary to understand why the average of three rolling distances should be obtained in each experiment.

How to get out of the experiment;

In order to solve the problem that how i roll is far away, it is a common method in scientific research to design experiments and practice and discover with problems. Children do experiments with slopes of different angles, and do several experiments with the slopes of each angle, and then take the average value, which can make the data more accurate, and then compare the results of each experiment and draw the conclusion of the problem.

I got something from the experiment: the different angles between the slope and the ground make the objects roll at different distances, some roll farther and some roll closer. By comparison, I know that how i roll is farther away, and I know that the same experiment needs to be repeated several times to make the data more reliable.

Homework design like this embodies the "three meetings" of the new curriculum standard, and will discover the world with mathematical eyes, describe the world with mathematical language and explain the world with mathematical thinking, which not only increases children's interest in learning mathematics, but also develops their mathematical literacy.