Unit 1: Measurement.

Understanding of 1, mm and decimeter;

(1) Estimate the length of common objects in centimeters, and deduce the length units of millimeters and decimeters in actual measurement.

(2) Through the measurement activities, we can actually feel how long 1mm and 1mm are, and we will use millimeters and decimeters as length units to estimate.

(3) Knowing the forward speed between meters, decimeters, centimeters and millimeters, we can choose the appropriate length units according to the specific situation and will use these length units for measurement.

(4) Be able to complete relevant calculations and applications, and develop the concept of space and hands-on operation ability.

2. Understanding of kilometers:

(1) Understand that the kilometer is a much larger unit of length than the meter, know how long it is about 1 kilometer, and get a preliminary understanding of the application of the kilometer in life.

(2) Grasp the propulsion rate between kilometers and meters, correctly convert and calculate, and solve related practical problems.

3, tons of understanding:

(1) Understand that tons are much larger than kilograms, know how heavy 1 ton is, and understand the application of mass unit tons in life.

(2) Grasp the forward speed among tons, kilograms and grams, correctly convert and calculate, and solve related practical problems.

(3) The quality of some common items can be estimated, and the appropriate quality unit can be selected according to the specific situation.