Master the quality units of grams, kilograms and tons. Feel the actual mass of grams, kilograms and tons, and be able to tell the mass of common objects in combination with specific situations. The relationship among kilograms, grams and tons and their simple conversion can solve simple practical problems. Master the relationship between kilograms, grams and tons, namely:

1 ton = 1000 kg, 1 kg = 1000 g, and can correctly convert between units. Understand the mass units of kilograms and grams, understand their actual mass, and establish the concepts of kilograms and grams.

2. Grasp the forward speed between kilograms and grams, and make simple conversion.

3. Through weighing, weighing and other activities, let students feel the weight initially, establish the concepts of kilograms and grams, and experience their respective weights.

4. Combining with practice, let students experience the application of grams and kilograms in life, and choose the appropriate weight unit for objects.

5. Cultivate students' ability to estimate their weight in activities. Including two aspects of ability, one is to choose the right weight unit, and the other is the accuracy of weight estimation.

6. Understand 1 kg = 1000 g, and learn simple conversion.

The kilogram can be recorded as kg, the gram as g, and the formula can be written as 1 kg = 1000 g.

7. The same object can be expressed in different weight units, for example, a watermelon weighs 2(kg), or it can be said that this watermelon weighs 2000(g).

8. Through actual weighing, let students know several common weighing tools: balance, bench scale and electronic scale. Learn to use weighing tools to weigh objects.