Measure the amount of liquids such as water, oil and drinks, usually in liters. L can be represented by the letter "l"
Less liquid is measured, usually in milliliters. ML can be represented by the letter "ml".
1L = 1000 ml (ml, ml)
For example, 4 1000 ml is 4000 ml, then 4 liters =4000 ml; There are two 1000 ml in 2000 ml, so 2000 ml =2 liters.
Different liquids have the same capacity, but not necessarily the same weight. 1 the weight of the liter of water is just1kg; 1 liter of milk weighs more than 1 kg; 1 liter of oil is less than 1 kg.
Teaching Design of "Understanding Promotion and mL"
Time: 8: 46 on August 24th, 2020.
Teaching content:
Know liters and milliliters.
Teaching objectives:
1. Knowledge and skills: In practical operation, I have experienced the process of understanding the concepts of capacity and measuring tools, as well as the understanding of "liter" and "milliliter".
2. Process and method: Understand the meaning of capacity, know "liter" and "milliliter", and know how to express "liter" and "milliliter" with letters; You can read the amount of liquid in the measuring cup and measuring cylinder.
3. Emotion, attitude and values: Actively participate in "playing with water" activities, and get a pleasant learning experience and math activity experience.
Teaching emphases and difficulties:
Teaching emphasis: understand the meaning of capacity, know "liter" and "milliliter", and know how to express "liter" and "milliliter" with letters.
Difficulties in teaching: being able to read the amount of liquid in measuring cups and measuring cylinders.
Teaching methods:
Inquiry and discovery, intuitive demonstration and question induction.
Teaching organization form:
Observation and discovery, hands-on operation, independent exploration, cooperation and exchange
Teaching process:
First, create a situation to arouse interest by setting doubts
This lesson starts from the reality of life: first, show three kinds of water cups, ask questions, arouse students' interest and stimulate their strong thirst for knowledge.
Second, experience and explore new knowledge.
1. Cognitive ability
(1) The teacher shows two glasses (one is tall and thin, the other is short and thick). In contrast, it will lead to "which cup contains more water?" Let the students observe and guess. When students express different opinions, ask the question of big-headed baby, and the whole class will discuss the methods of comparison.
(2) Group cooperation to carry out the "water filling" test, encourage students to actively cooperate, choose test methods, and guide students to pay attention to safety. When communicating the process and results of the experiment, let the students talk about how to do it and how to judge it. There may be many ways for students to experiment.
Students' methods will be affirmed and praised as long as they are reasonable. )
(3) On the basis of students' communication, put forward the concept of capacity, telling students that which cup contains more water is which cup has more capacity; The two cups contain as much water, so they have the same capacity.
2. Know the capacity unit.
(1) The teacher took out two bottles with the same height, different thicknesses and the same height of drinks in the bottles, and asked the students to observe "which bottle contains more drinks" first, and then asked the blue ghost mouse questions, which inspired the students to tell the way of ya ya. Then the whole class completes the operation and asks the students to describe the measurement results (if the students mention the measurement methods of measuring cylinder and measuring cup. Give affirmation first)
(2) Understand the measuring methods of measuring cups and measuring cylinders. First, let students know the scales and letters on measuring cups and measuring cylinders. Then, students observe measuring cups and measuring cylinders and find that they are characterized by graduation. Careful students will also find that the scale of measuring cylinder is uniform, and the scale of measuring cup is uneven. The teacher led the students to find that on the measuring cup, each cell represents 25ml, but the width gradually decreases to prepare for the next reading. After students' full observation and communication, it is pointed out that when measuring liquids, such as gasoline, drinks, potions, etc. Know "l" and "ml" and their corresponding letters in liters or milliliters, and tell me where I have seen liters or milliliters.
(3) Measure the quantity of two bottles of drinks with a cup or a measuring cylinder. The teacher's operation requires students to observe carefully, read the scale of the liquid level of the drink, and write the numbers on the blackboard. Reading scales is the difficulty of this course. In this link, students who read correctly can tell their own methods and realize students' teaching. In order to accurately read the scale of liquid level, we must first find out the numbers represented by each scale to realize student teaching. In order to reduce the reading error, we should pay attention to the correct method to guide students to read the contents of the measuring cup, that is, the line of sight should be flush with the liquid level of the measuring cup.