How to measure the amount of precipitation in a snowfall for third grade
How to measure the amount of precipitation in a snowfall for third graders
Measuring precipitation
A brief analysis of the textbook
Precipitation is a basic aspect of weather Characteristics are also important recording elements in the "Weather Calendar". From an early age, students try to use their senses to observe and judge rainfall conditions: light rain, moderate rain, heavy rain. This method of using sensory organs to judge the amount of precipitation will have certain errors, which leads to the tool of rain gauge. This lesson teaches students how meteorologists measure, record, and determine precipitation. In order to stimulate students' interest in observing precipitation and understand the working principle of a rain gauge, this lesson allows students to make a simple rain gauge and use it to measure and record precipitation.
Analysis of academic situation
Students have certain life experience with weather phenomena and know that rain is a form of precipitation, but it is difficult to understand that snow and hail are also precipitation. Making a simple rain gauge seems relatively simple. According to the hands-on ability and learning and understanding ability of third-year students, there will be certain errors in the production of the rain gauge. In particular, the alignment position of the 0 scale is difficult to operate, and the line of sight is not in line with the liquid level when reading. The horizontal height is difficult to unify, resulting in inaccurate precipitation measurement.
Teaching objectives
Scientific concept: Through observation and measurement, know that the rain gauge is a tool for measuring rainfall, understand the rain gauge, and learn to use the rain gauge.
Scientific thinking: Use the methods of data collection, analysis and induction to summarize the rainfall changes over a period of time and reason about weather characteristics.
Exploration and practice: Make a simple rain gauge, learn to use a simple rain gauge to measure rainfall, and complete the record of the "weather calendar"; use simple charts to organize and analyze weather information.
Attitude responsibility: During observation and measurement, students can be stimulated to be interested in studying weather phenomena and cultivate a scientific attitude to continue studying weather.
Teaching Important Points
Focus: Make a simple rain gauge and learn to use the rain gauge to measure rainfall.
Difficulty: Simulate the spraying method of rainfall and the eye level when reading.
Teaching preparation
Teacher: multimedia courseware, actual rain gauge.
Students: transparent straight cup, graduated tape (tape), watering can, sink.
Teaching process
1. Focus: knowledge preparation, revealing the topic (default 5 minutes)
Material preparation: reading materials about precipitation
1. Present knowledge about precipitation and let students read and understand.
Precipitation is an important feature of weather. Precipitation consists of two parts. One is the condensation of water vapor in the atmosphere directly on the ground or surface and low altitude, such as frost, dew, fog, etc., also known as horizontal precipitation; the other part is the condensation of water vapor falling from the air to the ground. , such as rain, snow, hail, etc., also called vertical precipitation. The ground observation specifications of the China National Meteorological Administration stipulate that horizontal precipitation is not treated as precipitation, and precipitation only refers to vertical precipitation.
2. Understand the amount of precipitation and common forms of precipitation.
The data that measures the amount of precipitation in an area is called precipitation. The unit of precipitation is millimeters.
Common forms of precipitation include rain, snow, hail, etc.
3. Introduce the precipitation measurement tool - rain gauge.
4. Reveal the topic: measuring precipitation. (Written on the blackboard)
The design intention is to use a few minutes at the beginning to introduce the knowledge about precipitation, so that students can understand that the precipitation in our country only refers to vertical precipitation, and eliminate unnecessary learning obstacles.
2. Exploration: Making and using a rain gauge (preset 25 minutes)
Material preparation: each set of transparent straight cups, graduated tape (tape), watering can, sink
1. Know and understand the rain gauge.
Understand the structure and working principle of the rain gauge by observing the pictures.
2. Learn the steps to make a simple rain gauge. (Picture on page 48 of the book)
Basic production process: (1) Choose a straight transparent cup; (2) Draw a vertical straight line outside the cup; (3) Use a transparent scale bar along the straight line Start from the bottom and align the 0 mark with the bottom of the cup.
3. Simulate rainfall and use a simple rain gauge.
(1) Watch the micro class, simulate rain, and use a rain gauge to measure the rainfall of this rain.
(2) Summary of how to use a simple rain gauge: Place the rain gauge on a horizontal table. Use a watering can to simulate precipitation and record the time. Read the scale with your eyes level with the liquid level. Convert to 24 hours to determine the rainfall level.
(3) Use a simple rain gauge to measure the amount of three simulated rainfalls, convert the three precipitation times into 24 hours, and determine the precipitation levels of the three rainfalls based on the rainfall level standards.
Design Intent The making of a rain gauge is the focus of this lesson. Key points are used to avoid errors and students learn to make a simple rain gauge and use the simple rain gauge to measure rainfall. It is particularly important to emphasize that when using a watering can to simulate precipitation, a certain distance must be maintained.
3. Discussion: Improve the rain gauge and measure snow precipitation (default 5 minutes)
1. What should you pay attention to when making a homemade rain gauge? What should we pay attention to when measuring rainfall?
(Default: The straight tube is transparent, the bottom of the cup should not be too thick, the scale bar should be straight, and the "0" scale should be aligned with the bottom of the cup.)
2. How to measure a field What about snow precipitation?
(Default: let all the snow melt into water first, and then take readings.)
The design intends to measure the amount of precipitation in a snow, which is difficult for students. Through discussion and guidance, students understood that all the snow should be melted into water, consistent with the standard of precipitation at the beginning.
4. Expansion: Measure rainfall for ten consecutive days (default 5 minutes)
Material preparation: students make their own rain gauge
1. Measure for ten consecutive days Local rainfall, and determine the rainfall level according to the "24-hour rainfall level standard".
2. Observe the rainfall histogram for 15 consecutive days and discover relevant information.
The design intends to use the methods of data collection, analysis and induction to summarize the rainfall changes over a period of time, reason about weather characteristics, and cultivate a scientific attitude for continuous weather research.
Troubleshooting
1. When making a rain gauge, is there a difference between a transparent straight wide-mouth cup and a straight narrow-mouth cup?
Because during the rainfall process, the rain falling from the sky is evenly distributed in every place on the ground within the rainfall range. If the large outdoor pool is regarded as a wide-mouthed cup, the small pool is regarded as a narrow-mouthed cup. , when it rains within 24 hours, the water received by the large pool is divided into several small pools with a diameter similar to that of the small pool, and their water levels are consistent. The water level height we read is the rainfall amount, so there is no difference.
2. When using a watering can to simulate rainfall, why should there be a certain distance between the spout of the watering can and the mouth of the cup?
When rain falls from high altitude, the rainfall is uniform everywhere within a certain range. The purpose of using a watering can to simulate rainfall is to ensure the uniformity of rainfall and to better illustrate the authenticity of rainfall, so it should be kept at a distance from the mouth of the cup.
3. Can the amount of rainfall in one rain replace the amount of rainfall in 24 hours?
If there is only one rain in 24 hours on a certain day, then this rain is the 24-hour rainfall. If it rains three times on a certain day, add the sum of the three rains to get the 24-hour rainfall.