The rational number multiplication test questions and answers in the first volume of the first day of junior high school I. Multiple choice questions (*** 14 small questions)
1. Calculation: 2? The result of (-3) is ()
B.﹣6 C.﹣ 1
Test center rational number multiplication.
Special calculation problems.
The analysis can be calculated according to the rational number multiplication rule.
Solution: 2? (﹣3)=﹣6;
So choose B.
This topic reviews the multiplication of rational numbers and grasps the multiplication law of rational numbers: the multiplication of two numbers, the same sign is positive, the different sign is negative, and the multiplication of absolute values is the key to solving problems.
2. Calculation: (-2)? The result of 3 is ()
A.﹣6 B.﹣ 1 C. 1 D.6
Test center rational number multiplication.
The analysis can be calculated according to the multiplication algorithm of rational numbers.
Solution: (-2)? 3=﹣2? 3=﹣6.
So choose a.
This topic examines the multiplication of rational numbers, which is a basic topic. Pay attention to the handling of symbols when calculating.
3. Calculation: 2? (﹣3)=( )
A.﹣6 B.﹣5 C.﹣ 1 D.6
Test center rational number multiplication.
The analysis can be calculated according to the multiplication algorithm of rational numbers.
Solution: 2? (﹣3)=﹣6.
So choose a.
This topic examines rational number multiplication, and memory algorithm is the key to solving problems.
4.(﹣2)? The result of 3 is ()
A.﹣5 b 1 c.﹣6 d . 6
Test center rational number multiplication.
Special calculation problems.
Analyze the positive sign and negative sign of the same symbol multiplied by two numbers, and then multiply by the absolute value to get the answer.
Solution: Original formula =-2? three
=﹣6.
So choose: C.
This topic reviews the multiplication of rational numbers, first determine the sign of the product, and then calculate the absolute value.
5. Calculation (-6)? The result of (-1) is equal to ()
B.﹣6 C. 1 D.﹣ 1
Test center rational number multiplication.
Special calculation problems.
The analysis can be calculated according to the multiplication algorithm of rational numbers.
Solution: (-6)? (﹣ 1),
=6? 1,
=6.
So choose: a.
Comment on this question to examine the multiplication of rational numbers, which is the basic question, and the memory algorithm is the key to solving the problem.
6.(﹣3)? The result of 3 is ()
A.-9th century BC D.-6
Test center rational number multiplication.
Analysis can get the answer according to the multiplication of two numbers and the negative sign.
Solution: Original formula =-3? 3=﹣9,
So choose: a.
This topic reviews the multiplication of rational numbers, first determines the sign of the product, and then performs the absolutely worthwhile operation.
7. calculation? 4? The result of (-2) is ()
B.﹣8
Test center rational number multiplication.
The analysis can be calculated according to the multiplication algorithm of rational numbers.
Solution: -4? (﹣2),
=4? 2,
=8.
So choose: a.
Comment on this question to examine the multiplication of rational numbers, which is the basic question, and the memory algorithm is the key to solving the problem.
8. The school building has to go through 20 steps from each floor to the next floor. The number of steps Xiao Ming has to take from the first floor to the fifth floor is ().
100
Test center rational number multiplication.
Analysis from the first floor to the fifth floor * * * passes through four floors, so multiply 20 by 4 and calculate the solution according to the multiplication algorithm of rational numbers.
Solution: The steps from the first floor to the fifth floor are: 20? (5﹣ 1)=80.
So choose B.
This question examines the multiplication of rational numbers. It should be noted that the number of layers passed is the floor minus 1.
9. Calculation (-1)? The result of 3 is ()
A.﹣3 B.﹣2
Test center rational number multiplication.
The analysis can be calculated according to the multiplication algorithm of rational numbers.
Solution: (-1)? 3=﹣ 1? 3=﹣3.
So choose a.
This topic examines the multiplication of rational numbers, which is a basic topic. Pay attention to the handling of symbols when calculating.
10. Formula (-1)? (﹣3 )? What is the value? ( )
A.B. C. D。
Test center rational number multiplication.
According to the multiplication law of rational numbers, the symbol is determined first and then multiplied by the absolute value.
Therefore, choose: d.
This question examines the multiplication of rational numbers, and mastering the multiplication rule is the key to solving the problem. When calculating, first determine the symbol and then multiply it by the absolute value.
1 1. The following operation result is correct ()
A.﹣87? (﹣83)=722 1 b.﹣2.68﹣7.42=﹣ 10
C.3.77﹣7. 1 1=﹣4.66
Test site rational number multiplication; Comparison of rational numbers; Rational number subtraction.
Special calculation problems.
We can make a judgment by analyzing the calculation results of the original formula.
Solution: a, the original formula =722 1, correct;
B, the original formula =- 10. 1, wrong;
C, original type =-3.34, error;
d、﹣& gt； Mistakes,
So choose one
This topic reviews the multiplication, comparison and subtraction of rational numbers. Mastering the algorithm skillfully is the key to solve this problem.
12. If □? (-2) = 1, then a real number in □ should be ().
A.B.2 C.﹣2 D.﹣
Test center rational number multiplication.
Special calculation problems.
According to the analysis, two numbers whose product is 1 are reciprocal solutions.
Solution: ∵? (﹣2)= 1,
? □ Fill in the real number should be □.
Therefore, choose: d.
Comment on this question to examine the multiplication of rational numbers, which is a basic question, pay attention to the definition of reciprocal.
13.743 formula? 369﹣74 1? What is the value of 370? ( )
A.﹣3 B.﹣2
Test center rational number multiplication.
According to the law of multiplication and distribution, the analysis can be simple and convenient, and the answer can be obtained according to the subtraction of rational numbers.
Solution: Original formula =743? (370﹣ 1)﹣74 1? 370
=370? (743﹣74 1)﹣743
=370? 2﹣743=﹣3,
So choose: a.
This topic examines the multiplication of rational numbers, and the law of multiplication and distribution is the key to solving problems.
14. If among all the factors of integer A, the positive integer factor less than 25 is 1, 2, 3, 4, 6, 8, 12, 16, 24, what is the greatest common factor between A and 720? ( )
A.24 B.48 C.72 D.240
Test center rational number multiplication.
Analyze according to the multiplication of rational numbers, find the least common multiple of all factors, and then find the greatest common factor with 720, which is the greatest common factor.
Solution: that least common multiple of 1, 2, 3, 4, 6, 8, 12, 16, 24 is 48,
The greatest common factor of 48 and 720 is 48,
So the greatest common divisor of A and 720 is 48.
So choose B.
In this paper, the multiplication of rational numbers is investigated, and it is the key to solve the problem to determine the least common multiple of all factors.