Teaching objectives:
1, knowing the capacity unit milliliter, knowing that milliliter is a relatively small capacity unit.
2. Grasp the feeding speed between liters and milliliters, and know that 1 liter = 1000 milliliters.
Teaching preparation: students preview and prepare measuring cups, droppers, measuring cylinders, water, etc.
Teaching process:
First, understand the preview:
Do you know what we are going to learn in this class through preview? What do you know?
Answer the blackboard with the students: ml
Students may know that milliliter can be represented by the letter ml; 1 l = 1000 ml; ……
Second, know 1 ml
1. Take the measuring cylinder. Introduction: The minimum scale of this measuring cylinder is 5 ml. Now we need to use it and this dropper to calculate how many drops there are in 1 ml.
2. Drop water into the measuring cylinder with a dropper. Count. A few drops is about 1 ml.
How much do you know about milliliter through this experiment?
4. introduce the container for measuring milliliters in life: sometimes when you are sick, you should drink some potions. (Take a medicine bottle) Reading: Adults drink 15 ~ 20ml each time. Q: I don't have a measuring cup. How can I find this 15~20 ml potion?
Take the most common spoon in life, fill it with 1 spoon of water and pour it into the measuring cylinder. It is about 10 ml.
Point out: This spoon is something we use every day. Now will you use it to find the right amount of potion?
Third, finish thinking and doing 1, 2:
1. How many milliliters of medicine are there in each container below?
It is pointed out that we can drink more and drink less, but we should not be a little careless in using drugs, and we must strictly abide by the regulations when using drugs. Here are some common specifications. How many milliliters are they?
2, the teacher measured a 50 ml with a measuring cylinder, and then poured it into an ordinary disposable transparent cup, let the students feel its height, and then let the students imagine what the water level might be if they poured it into these containers in question.
Practice at home: scoop 50 ml of water with the spoon you just met (10 ml) and pour it into these containers to see where the water surface is.
Four, liter and milliliter ratio
1. Show a 500ml measuring cup. Please observe the scale on the measuring cup, pointing to100ml,150ml, 250ml, 400ml and 500ml respectively.
2. Pour 1 liter of water into the measuring cup to see how many cups can be poured. (two cups)
3. Q: How many milliliters is 1 liter?
4. The students who were named answered that the blackboard writing (1 liter = 1000 ml) indicated that the forward speed of liters and milliliters was 1000.
5. Exercise: 2000ml = () L4000ml = () L.
9 l = () ml 10 l = () ml.
Fifth, finish thinking and do 3, 4, 5:
1, tell me how many bottles of each of the following drinks are needed, which is exactly 1 liter:
Please list the complete solutions. Tell the reason for the first communication problem.
2. Pour out 100ml beverage and count how many mouthfuls you need to drink before you finish it. Calculate again, how many milliliters is there in a sip?
First of all: how to drink this experiment? Then invite more students to drink this 100ml water naturally. Do the math.
3. Complete thinking and action 4
(1) Students do it independently.
(2) communication
6. Guess what
Students freely exchange their feelings after reading.
After-class notes: "Establishment of the concept of 1ml", let students observe the situation of 1ml in measuring tools and bottle caps, and put it into the dropper, so that each student can clearly see the amount of 1ml, which is of interest to students. Knowing the capacity of an ordinary spoon is about 10 ml, which can help students find and know ml more easily in their lives. This is a very good learning tool.
Post-grant comments:
The first two classes give me the biggest feeling that the teaching ability unit should take hands-on operation and physical demonstration as the main teaching and learning methods. So before class, I used the student group to collect a large number of physical containers that appeared in practice and showed them to all my classmates in class. Through observation, students actually feel that "1ml" is a very small unit of capacity, which is the actual size of various small-capacity containers.