Sums within 20
Math
Sums within 20
Today is Saturday, May 30th, 2020. We had a Math lesson - Sums within 20.
Q: What are these animals?
A: They are dinosaurs.
Q:How many dinosaurs are there in the forest?
A: There are five dinosaurs in the forest.
Q: Five and how many more is ten?
A: Five and five more is ten.
Let’s learn about the dinosaur bones.
A: They are skull and teeth.
A: They are plates.
A: They are ribs.
Q: We can use tools to find dinosaur bones. What are these tools?
A: They are shovel,hammer,fork and brush.
Professor find some dinosaur teeth, let’s help him to count.
Q: How many dinosaur teeth are there in blue tray?
Q: How many dinosaur teeth are there in red tray?
Q: How many dinosaur teeth are there in all?
A: Ten and three more is thirteen.
So there are 13 dinosaur teeth altogether.
Q: Can you use three ways to express this number sentence?
A1:Ten and ten is twenty.
A2:Ten plus ten equals twenty.
A3:The sum of ten and ten is twenty.
Let’s count dinosaur plates.
There are 17 plates altogether and some of them are missing.
Q: 10 and what number is 17?
A:10 and 7 more is 17.
So we need 7 more plates.
Next, let’s check all the tools
18 tools are loaded on the truck. 10 of them are forks.
Q: How many tools are there on the left side?
What number and 10 more is 18?
A:8 and 10 more is 18.
So there are 8 tools on the left side.
Now, let’s tidy up this park by recycling!
Q: How many bottles are there? How many cans are there?
A: There are ... bottles, there are ... cans.
Q: How many bottles and cans are there in total?
A: There are ... bottles and cans in total.
We can put bottles and cans into recycling machine.
Eight blue blocks can show eight bottles.
Six red blocks can show six cans.
Eight and six more is greater than ten.
Q: How to get fourteen?
A: Ten and four more is fourteen. Eight and six more is fourteen.
本课教学目标
1. 运用估算法尝试解决问题；
2.学习20以内的加法，其中一个加数为10；
3.运用20以内加法解决课件中的数学问题；
本课关键词
dinosaur，skull（头盖骨），teeth，plate（骨板），ribs（肋骨），bones，tools，hammer，shovel，fork，brush，bottles，cans
本课作业
1. 语音作业-复习语音，自己回答语音中的问题。
2. 笔头作业-完成下发的作业纸