(People's Education Edition) Multiplication Formula and Answer of Mathematics 2-6 in the First Volume of Senior Two (4)
1. The tricycle that children ride has three wheels. How many wheels do two such tricycles have? (List the formulas and write the formulas)
Second, Xiao Gang's mother bought four bags of rice vinegar in the supermarket, each with 2 yuan. I also bought a pack of biscuits and spent 5 yuan.
(1) How much did Xiaogang's mother spend on these things?
(2) How much did it cost to buy vinegar more than cookies?
Third, make up a question according to the picture.
Fourth, choose the right conditions and questions, make up an application question, and then answer it.
(See who makes up the most questions)
1 Conditional question A picture costs 50 cents, and a * * *, how many birds did you draw?
There are four. How much is a * * *?
There are four birds in a picture. How much is left? * * * With money from 3 yuan,
Reference answer 1. Formula: 3+3 = 6 or 3 × 2 = 6. Formula: two or three makes six.
Second, analysis: this question is suitable for intermediate level students. The purpose of this question is: (1) review the knowledge of multiplication and division learned in this lesson; (2) Compare the knowledge of multiplication and division learned in this lesson. Solution: (1) 4× 2+5 = 13 (yuan) (2) 4× 2-5 = 3 (yuan) Extension: The process of understanding the meaning of this question is mainly aimed at middle-level students, so students can give full play to their subjective initiative in calculation, come up with different calculation methods and get the same answer. The main examples of this step are: (1) 4× 2+5 = 4× 2+(4+1) = 4× 3+1=12+1=13.
Analysis: This question is suitable for middle school students.
The purpose of designing this problem is to (1) review and consolidate the multiplication application problem solved in one step. (2) Improve students' oral expression ability. (3) Cultivate students' flexible thinking ability. Answer:
(1) Method 1: small square pendulum ☆, 5 in each row ☆, 3 rows like this, one * * *, how many are used? 5× 3 = 15 (pieces) answer: one * * *, and 15 pieces were used. (2)
Method 2: small square pendulum ☆, 3 in each column ☆, 5 columns like this, one * * *, how many are used? 3× 5 = 15 (pieces) answer: one * * *, and 15 pieces were used.
Fourth, analysis: this question is suitable for students of above average.
The purpose of designing this question is:
(1) Make students more familiar with the structure of multiplication application problems solved in one step.
(2) We can choose suitable conditions and problems from many conditions and problems to write corresponding application problems (such problems are much more difficult than drawing pictures to write problems).
(3) Cultivate students' good habit of examining questions. If the units are not unified, they should be summarized.
(4) Give full consideration to the problem of "not being capped", so that children with strong abilities can give full play to their abilities (children with strong abilities can choose three conditions and make up an application problem of two-step calculation). Solutions: (The order of solutions is sorted by difficulty)
(1) There are four birds in a picture. How many birds did a * * * draw? 4× 4 = 16 (only)
(2) A piece of paper costs fifty cents, and there are four pieces. How much is a * * *? 5× 4 = 20 (angle) 20 angle = 2 yuan.
(3) A * * * has 3 yuan money, a piece of paper costs 50 cents, and there are four. How much money is left?
Method 1: 5× 4 = 20 (angle) 20 angle = 2 yuan 3-2 = 1 (yuan)
Method 2: 3 yuan = 30 angle 5× 4 = 20 (angle) 30-20 = 10 (angle).