Tire Tracks in Sand 沙地上的輪胎足跡
So recently, we've found a great new toy. It's called Kinetic Sand. It is similar to Playdoh in many ways, yet is something totally different. It is sand. It packs down just like sand and feels just like sand. The cool thing is that it's clean, easy to clean up and can be packed together and taken apart a million times.
We've been playing with our sand for the past couple of evening. Last night, we took a look at the different footprints Oliver's toys would leave in the sand and how they were different. Today, Oli was ready to go and curious if the different trucks and cars he had would leave different tracks as well. Sounds like a great question to me.
We started first by packing down the sand a bit. We had to play around to figure out how much we needed to pack it down to get the clearest tire marks. Next, it was time to pick a truck with some recognizable tire tracks. The excavator seemed like a logical place to start.
It left very clear tracks. All right, time to try the other ones now. We tried big cars and little cars. We learned that we could tell if the car was big or small by how wide apart its tire tracks were.
Each car had a different kind of pattern that it left. We looked closely at the patterns and compared them to what the tires looked like and started to figure out why every pattern was different.
Then, we saw a huge difference when we used the steam roller. It was totally smooth. We were able to compare it to one of the books that we have about building roads and all of the different vehicles.
Finally, after we had tried out all of the cars, we decided to play a game. Oliver covered his eyes and I ran a car over the sand. When he opened his eyes, he had to look at the tracks and then look at the tires of the cars to figure out which one had made the track.