What’s the weight?

Contents: Grade 3 Book A Unit 3 Kilogram and Gram
Teaching Aids:
1、Get to know the unit: Kilogram and Gram;
2、Grasp 1kg = 1000 g ;
3、Explore where Math and real life meet. Learn to use Math in daily life. Foster their consciousness of using and improving their problem -solving.
Teaching Resources: 6 kitchen scales, balances , fruits and commodities
Teaching Procedure:
一、Investigation report
We have been to the market last week and have weighed a lot of things. You written the weight of the object in the cards. So classify these cards according to Kg and g. Which group would like to report your investigation?
Any gains do you have in this investigation ? Any questions?
Why does something use kg as the unit? Why does something use g as the unit?
二、Get to know the unit: kg and g.
1、How heavy is 1kg? Two bags of salt are 1kg. Let the students weight in the hand.
2、How about the fruits、vegetables and other commodities ? How many is 1kg?Try to weigh in the group.
3、Report.
4、Put them in your hand, how does it feel?
5、How heavy is 1g? The teacher use the balance to weigh 1g’s beans
6、Put them in your hand, how does it feel?
三、Exercise：Choice
1、An egg is about ( ).
60g 600g 6kg
2、A watermelon is about ( )
30g 300g 3kg
3、Billy is about ( )
24g 240g 24kg
四、competition
Each time asks four students to take part in the competition. The teacher will show something. Each student weighs in the hand, guessing how heavy is it? Then write the answer on the paper. Let’s see who can estimate it right. Other students will estimate it by the eyesight.
五、Group activity.
Do you want to know other thing’s weight? It’s time for the group. Choose your favorite things. Weight in the hand first and guess how heavy it is? Then weigh on the scale. Let’s see whose answer is more close to the right answer?
六、Question
Any questions about kg and g?
七、Self assessment
Think over your own performance in this class. Are you satisfied with yourself? Make a self assessment, then fill in the paper.
八、How heavy you are? Do you want to know? Try to weigh yourself on the scale.

Experiment Record

Object
物品名称
Estimation
我们的估计
Actual weight
称量结果
Survey Chart
Group: Members：
Object
物品名称
Quantity
数量
Weight（unit）
重量
Weight it in the hand
掂一掂


Yes No
Our gains（我们的收获）：


Our doubts（我们的疑问）：