Mathematics Teaching Plan of Decimal Multiplying Decimal 1 teaching material analysis;
The growing point of learning the calculation method of decimal multiplication is integer multiplication. However, "How to get the original product after integer multiplication" needs a rigorous reasoning process, and the textbook arranges two inquiry activities: the first time, in the example 1, we think about the three arrows in the dotted box and the meanings of "× 10" and "∫ 100" to help students go through the reasoning process. The second time in "Try it", let the students fill in the blanks in the brackets above the three arrows, and write the vertical product on the left for independent reasoning. After two explorations, we compare the decimal places of the product of two factors in each question, and find that "two factors have several decimal places, and the product has several decimal places". On the basis of understanding arithmetic, the operation method of calculating decimal point in product is obtained. At the same time, through inductive reasoning, the calculation rules of fractional multiplication are summarized.
Analysis of learning situation:
Teaching decimal multiplication and decimal division with integers is based on students' learning the meaning, nature and addition and subtraction of decimal. Decimal multiplication and division is widely used in daily life and further study. Decimal multiplication of integers and fractional division of integers are not only important components of fractional multiplication and division, but also the basis for further study and exploration of fractional multiplication and division. Students master the calculation method of integer multiplication and division, the changing law of product and quotient, and the calculation method of integer multiplication and division and fractional division, which is helpful for students to fully master the calculation method of fractional multiplication and division and understand the relevant operation rules, and improve their ability to solve simple practical problems by using four operations.
Teaching objectives:
1. Understand the meaning of decimal multiplication and master the calculation rules of decimal multiplication.
2. Initially cultivate students' ability of analogy and abstract generalization.
3. Enable students to further understand the internal relationship between mathematical knowledge, feel the fun of mathematical inquiry activities, and enhance their confidence in learning mathematics well.
Teaching emphases and difficulties:
Master the method of multiplying decimal by decimal, be skilled in written calculation and solve practical problems. Master the handling method of 0 after decimal point.
Decimal Multiplication Decimal Mathematics Teaching Plan 2 Teaching Objectives
1, master the calculation rules of fractional multiplication, and let students master the decimal places of the product. If there are not enough digits, they should be supplemented with 0.
2. Correctly calculate the fractional multiplication to improve the calculation ability.
3. Cultivate students' abilities of transfer, analogy and generalization, as well as their ability to solve new problems by using what they have learned.
Emphasis and difficulty in teaching
Teaching focus
Calculation rules of decimal multiplication.
Teaching difficulties
In decimal multiplication, the decimal places and decimal points of the product are located. If the number of decimal places of the product is not enough, it should be preceded by 0.
teaching tool
Whiteboard courseware
teaching process
First, introduce the attempt.
1. Show pictures: Students, the publicity column on our campus needs painting recently. Can you help me calculate how much paint I need? How to go public?
Step 2 try to calculate
What is the difference between the observation formula and the formula learned earlier?
This is what we are going to learn "decimal times decimal". These two factors are decimals. How to calculate them? Discuss with your deskmate, and then try to practice and name the blackboard by yourself.
3. 1.2×0.8. How did you calculate it just now?
Guide students to draw pictures (first expand the multiplicand 1.2 10 times into 12 times, and expand the product 10 times; Then the multiplier is expanded by 0.8 10 times to 8, and the product is expanded by 10 times. At this point, the product is enlarged by 10 × 10 times. Find the original product, and then subtract the product 96 by 100 times. )
4. Observe, what is the relationship between the factor and the decimal places of the product? The sum of the digits of the factor is equal to the decimal digits of the product. Think about it: How many decimal places does the product of 6.05×0.82 have? What about 6.052×0.82?
5. Summarize the calculation method of decimal multiplication.
Second, teaching examples 4
Please do the following set of exercises.
(1) practice.
(2) Guide students to observe and think.
How to calculate it? Calculate the product by integer multiplication first, and then put the decimal point on the product point. )
(2) What is the decimal point? (A factor * * * has several decimal places. Just count the decimal places from the rightmost side of the product. )
③ What did you find when calculating 0.56×0.04? So how to calculate the decimal point when the multiplied product has insufficient decimal places? (Add 0 in front, and then point the decimal point. )
Through the above study, who can tell in his own words what the calculation rules of fractional multiplication are?
(3) According to the students' answers, summarize the calculation rules on P5 page abstractly step by step, and ask the students to open their textbooks and read the rules together. (sketches and marks)
Summary after class
What did you learn in this class?
homework
According to 1056×27=285 12, write the product of the following questions.
105.6×2.7= 10.56×0.27= 0. 1056×27= 1.056×0.27=