<p><b><u>Seesaw cents</u></b></p><p><b>Materials：</b></p><ol><li>rectangular pencil eraser</li><li>Hard plastic ruler</li><li>Some coins.</li></ol><p><br></p><p><b>Steps: </b></p><ol><li>Set the eraser on its long, narrow edge on a level table or desk.</li><li>Place the ruler across the eraser so it looks like a seesaw and can rock back and forth. The ruler now is a lever, and the eraser is its fulcrum. The 7. 5-Centimeter mark of the ruler should be right above the eraser.This means that half the ruler is on each side of the eraser. The ruler should be able to balance this way, but if it can't, you can move it a little to the left or right until it balances.</li><li>Place two coins on one end of the ruler. When you put them on, the ruler will tip toward that side. Now put two coins on the other side. when you do this, the ruler should tip back and balanced again. The pennies are pushing down the same amount on both sides of the ruler. <b>Since the ruler is the same length on each side, having the same amount of push on each side will make its balance, This is like when you and your friend are on a seesaw. </b></li><li>Carefully lift the ruler and move it so the 8. 5-centimeter mark is now on top of the eraser. Will it balance with two coins on each side anymore? probably not. The longer side will go down. Where will you have to add coins to make it balance? Add coins - one at a time - to the shorter side of the ruler until it balances again. How many does it take? Two coins on the longer side can bbalancfour, five even six pennies on the short side. </li><li>Now carefully move the ruler so the 9. 5-centimeter mark is now over the eraser. keep two coins on the long side, Add coins to the short side until it balances again.How many coins did it take the time? Two coins can balance a whole stack of coins on the other side if the fulcrum is close to the stack.</li></ol><p><br></p><p> <b>This experiment shows how you can lift heavy things using a lever . if the fulcrum is much closer to the heavy thing than it is to you, it won't take a big push on your side to lift up the other side. Now you just ne</b>ed to find that elephant to lift.</p> <p>手工两个</p> <p><b><u>Building a 3D pyramid. </u></b></p><p><br></p><p>Using bricks and a special paste called <b>mortar砂浆</b> to create structures is called <b>masonry</b>.Mortar is what holds the bricks together. It is usually made of a powdery substance called cement mixed with fine sand and water. you can build your own masonry with sugar cubes and sticky tack.We do not have sugar cubes, so we use super light clay cubes instead.</p><p><br></p><p><b>Using bricks</b></p><p> Many buildings are put together using bricks. bricks are one of the strongest and longest lasting materials, which is why they have been used for building for thousands of years. House bricks are made from clay and baked in an oven to make them hard.</p><p><br></p><p><b>We will need</b></p><p>Super light clay cubes </p><p>sticky tack</p><p><br></p><p><b>Steps: </b></p><ol><li>Take your first cube and add a small ball of sticky tack to one side.Or we can use white clay instead. Be careful not to press too hard or the sugar will change its shape.</li><li>Repeat step one until you have a roll of four cubes . you should have a piece of sticky tack between each cube. Try to make sure the gap between the cubes is as thin as possible </li><li>now start building upwards, putting each cube above and between the two cubes beneath it.Try making a 3D pyramid. </li></ol><p><br></p><p>How stable is your pyramid ? do you notice any weak points?</p> <p><b><u>Egyptian sarcophagus</u></b></p> <p>架子鼓练习</p><p>计算</p><p>篮球课</p><p>打水仗</p> <p><b><u>网课一节</u></b></p><p>新囤了贝达，目前更喜欢的还是伴鱼，我找的老师就是这么好😎</p>