Finally came to the eighth lesson. It has been almost two weeks since the seventh lesson this time, and the interval is actually a bit long. So I plan to review the previous knowledge points before starting, to test how much the children can remember, and to warm up before class. So I browsed through the script I wrote before to see what I did. In the process of watching it, I suddenly thought of something. I am already used to programming thinking and the operating mode of the program, but the kid is not familiar with these. I didn’t even think about whether he could understand Understand how the program works? That is to say, what does the block in the script area, the block in the loop mean, does he understand?
It seems that there are two key points of investigation. First, to review the previous content. Second, to see which step the children have realized about the implementation of the building blocks in the script area? And I have to slow down the speed of progress a little, and strengthen the repetitive training of the content. Because of the understanding of online Scratch training during this period, basically the content of my first game has already been taught online for a year. Of course, after one year, it means that the children who are learning can do all the content in the game by themselves, instead of teaching them hand in hand.
Well, not much nonsense, review the summary of the first step.
The first is the content of the review. I feel that the memory of the children is still very reliable. Simply recall, the content of the previous lesson and the function of the building blocks themselves will be recalled quickly. Then I asked the children with a feeling of apprehension. "Do you know how these blocks work? Do you know the order in which they work?" The answer is a decisive "don't know". I know you don't understand, so don't be so arrogant. I had to slowly start to explain the running process of the blocks, which blocks are only executed at the beginning of the game, which blocks are executed in a loop, the order of the loop execution, and so on.
Later, I found out that the children actually understand the operation of the building blocks. If they didn't know before, they probably didn't know what I asked. After the explanation, the children realize the execution of the building blocks and the difference between the internal and external building blocks in the circulation, so they can proceed to the next step with confidence.
Squidward’s program will be modified again. Previously, Squidward’s facing direction was fixed, but now it has to be changed to a random direction. The concept of randomness is involved here, which must be explained carefully. First drag over the blocks of random numbers
What does it mean to take a random number between 1 and 10? Explain carefully, and ask which numbers belong between 1 and 10? This range can be changed, but it needs to be determined according to the actual situation. The problem we are currently encountering is to modify the direction that the octopus faces when it comes out of the field to a random direction, then the range of the direction is -179 degrees to 180 degrees, so the range of the random number blocks is -179 to 180
Why this range? It doesn't matter, explain in the above picture again, it doesn't matter how many times, as long as the impression is deepened.
The modification of the octopus is basically completed. The remaining task is to modify the size of the character in the program. By simply reminding the area where the building blocks are located, the children found and modified the size by themselves. Why do you have to modify it here? The children are puzzled. Haven't I already modified the character's control area? Explain patiently to prevent the size of the character interface from being accidentally changed. After we use building blocks to modify it, we can ensure that the size of the character is the fixed value we want every time we run the game. Try to modify the character interface and run the game again, very good, the octopus has changed from huge to the size we hoped for.
The final building block of the octopus is as follows:
After this is done move on to the next step, creating more octopuses. When I proposed this idea, the children suddenly realized that they should save all the building blocks of this octopus as a self-made building block, so that they can be used many times. Even after listening to the content of self-made building blocks, I still remember the concept of function. But not today, we want more octopus, just a simple step:
repeat twice, and done.
Three neat octopuses, because the copied octopuses have the same shape, the children changed the shape by themselves. Then we ran the game, and the three octopuses slid across the screen at a very fast speed. It was really difficult to escape, and the game basically ended within 2 seconds. Because the number of moving steps inside the loop body is 10 steps per cycle, the three octopuses are really happy to run at this speed. How to do it? The kid thought about it for a while, and changed the number of steps with an unskilled mouse, decisively changing it to 1. The turtle-moving Squidward is no longer a threat.
Finally it was the turn of the stars. Let the children do the simplest operation by themselves. First, explain the movement of the stars. First, they appear randomly at a certain position on the screen. When the puppy touches the star, the star disappears and reappears at a random position on the screen. I helped the children find all the building blocks needed for the stars, and let the children build the building blocks by themselves
. With the previous foundation, it really didn't take much effort to build these building blocks, and the children completed the task relatively easily. Running the game, well, it feels good.
I don't know if I remembered the pattern or really understood it, but I was a little surprised by the kid's performance today. But no matter what the situation is, the repeated exercises and patterns are for him to remember. There are many similar operations in the future, I believe you will become more and more familiar with it.
Then I went a step further and reintroduced the topic of random numbers and coordinates. First of all, I told him that I want the stars not to appear in random positions every time they come out, but in a fixed position, and then I asked him to drag the stars to a position he likes, and then I helped him find and use this building block to replace the
moving Blocks in a random position, and then let him run the game, and he found that the star went to a place that he didn't choose, why? Drag the star to the child's favorite position again. At this time, I told him to move to x and y and need to fill in the appropriate coordinate values so that the star can come to the designated position when the game is running. Just as I was about to tell him that he should get it from there When the values of x and y were reached, the children suddenly realized that they found the current coordinates of the stars, and then filled them in the building blocks.
This time, no matter how you run the game, the stars will return to the original designated position every time. Although this content has actually appeared many times, it is only now that the children have a relatively deep impression and begin to have a corresponding concept of coordinates and positions.
This is followed by retraining with random numbers. I told the children that I want to use the move to x, y coordinate block to achieve the same function as moving to a random position block, then drag out two random number blocks, and tell the children to place them in the move x, y coordinate block.
Then we ran the game together and found that the positions where the stars appeared basically did not change, and did not randomly appear anywhere on the screen. What's going on? I showed the coordinate background image again, and talked about the relationship between coordinates and position again, and learned how the range of x and y values changes on the position.
Let the children drag the stars to the lower left corner, upper right corner, upper left corner, and upper right corner to see the changes in xy. Although the children listened very carefully, they should still half understand. It doesn't matter, there are still many opportunities, and finally we completed this task.
This concludes the eighth lesson.