(Student activities)
Teacher: How much do you weigh this bag of red beans in groups?
Health: 200 grams.
Teacher: Please check the weight of this bag of peanuts again.
(Student activities)
Teacher: What's the weight of this bag of peanuts again?
Health: 500 grams.
Teacher: Would you please weigh this bag of sand again?
(Student activities)
Teacher: How much does this bag of red beans weigh?
Health: 2 kg.
Teacher: 1 How much does the apple weigh? Please weigh the apples before weighing them, and then say how many apples are there 1 kg.
Fourth, application expansion.
Teacher: The teacher brought an animated film "Accompanying Glass" to the students. do you want to see it ?
Animation: On Sunday, Piggy and Smart Dog go to Huahu Restaurant to drink. Piggy accidentally broke Huahu's cup. Huahu wants to knock the pig and ask the pig to accompany him 100 glasses. Facing the broken glass all over the floor, no one can tell how many glasses were broken.
Let the students uphold justice for pigs, speak freely and make suggestions.
Play the animation again: the clever dog came up with a clever idea. Weigh a intact glass (200g) first, then broken glass (1000g).
Ask the students to calculate how many cups the pig should accompany.
Verb (abbreviation of verb) summary after class
What's new in this lesson? How do you feel about learning new knowledge? There is nothing you don't understand.
[after-class reflection]
Gram and kilogram are two unfamiliar and familiar concepts for sophomore students. Before class, I asked my classmates to go to the shopping mall for a practical investigation, which made them feel that mathematics was everywhere around them, and at the same time let them initially establish the quality concept of grams and kilograms. Let the students know the progress speed between grams and kilograms. I didn't tell the students 1kg = 1000g directly, but let them sum up 1kg = 1000g by doing experiments. It fully embodies the process objectives advocated by the new curriculum standards. In the exercise part, students have a deeper understanding of the quality concepts of grams and kilograms by weighing, estimating and weighing, and cultivate their estimation consciousness. At the end of class, I asked students to give advice for piggy, which cultivated students' divergent thinking and problem-solving ability, enhanced students' awareness of life and realized the application value of knowledge.
Students are in an active learning state from beginning to end in a relaxed and happy learning atmosphere. Students turn passivity into initiative and truly become the masters of mathematics learning.