Unit teaching content: understanding of millimeters and decimeters, understanding of kilometers and understanding of tons.

Unit teaching objectives:

1, so that students can experience the actual measurement process, know the length units of millimeter, decimeter and kilometer, and establish the length concepts of 1 millimeter, 1 decimeter and 1 kilometer. Understand the quality unit ton and establish the quality concept of 1 ton.

2. Make students understand the relationship between commonly used length units and quality units, make simple unit conversion, and select units appropriately.

3. Enable students to estimate the length and mass of some objects and choose different methods to measure them.

4. In practice, enhance students' awareness of cooperation and communication, improve operational skills and develop practical ability.

Key points of unit teaching:

Establish the length concepts of 1mm, 1mm and 1km. Understand the quality unit ton and establish the quality concept of 1 ton.

Difficulties in unit teaching:

Will choose different measurement methods, so that students can estimate the length and mass of some objects.

Prepare unit teaching AIDS and learning tools:

Coin 1 piece (1, 2 or 5), magnetic card 1 piece (telephone card, store credit card or savings card), student ruler, paper clip, pencil case, math book, pencil or signature pen, etc.

Unit category arrangement:

Kilometers of knowledge ... 4 class hours

A lot of understanding ... 3 class hours.