Junior one mathematics

Proposer: Reviewer: Yu.

First, multiple-choice questions (2 points for each question, ***20 points)

1. The following statement is true ()

A. rational numbers are either positive or negative.

B. Rational numbers can be integers or fractions.

C. Rational numbers refer to five categories: integer, fraction, positive number, negative number and zero.

D. None of the above answers are correct.

2. Calculation: -3+(-2)= ()

A.5 B. 1 C.-5 D. 1

3. A car starts from Station A, travels 40 kilometers east, and then travels 30 kilometers west.

At this time, the position of the car is ()

70km east of Station A and 10km east of bilibili.

C. west of station a10km, 70km west of station d.a.

4. The rational number between -3 and -7 on the number axis is ()

A. 1 B.2 C.3 D

5. If the absolute value of a number is equal to the reciprocal of this number, then this number is ().

A. positive number B. negative number C. non-positive number D. non-negative number

6. If ∣ x ∣ = 2, ∣ y ∣ = 1, then ∣x+y∣= ()

A.3b. 1 c.3 or 1 d.3 or 1.

7. In 1,-1 and -2, the maximum sum of any two numbers is ().

A. 1 B.0 C.- 1 D.-3

8. If the sum of two rational numbers is positive and the product is negative, then these two rational numbers are 8. If the sum of two rational numbers is positive and the product is negative, then these two rational numbers &; (=NationalBureauofStandards)

p； ( )

A. they are all positive numbers. B. all negative numbers.

C. One is positive and the other is negative, and the absolute value of the positive number is large; D. One is positive and the other is negative, and the absolute value of negative numbers is large.

9. As shown in the figure (1), what is its circumference ()?

28 C.29 D.30

Figure (1)

10. Fold the paper shown in Figure (2) into a cube, and the sum of three numbers at the same vertex.

The maximum value is ()

A. 14 ….. 15

Figure (2)

2. Fill in the blanks (2 points for each question, ***38 points)

The reciprocal of 1 -Yes.-The absolute value of the reciprocal.

2. Point A and point B on the number axis represent -3, 1 respectively, so the distance between point A and point B is.

3. Calculation: ∣-5 ∣-∣-2 ∣ =.

4. Fill in the following figures in the corresponding brackets:

-7,3.5,-3. 14,? 8? 9,0, - , ,0.03, 10,-5℅,-

Natural number set: {…}; Integer set: {…}

Non-negative set: {…}; Negative score set: {…}

Even set: {…}; Odd set {…}

5. The number represented by a point with a distance of -2 3 units on the number axis is.

6. If =- 1, the reciprocal of a is. If a-3 and a+ 1 are reciprocal, then a is.

7. Points representing integers on the number axis are called the whole point, and the unit length of a number axis is 1 cm. If a line segment AB with a length of 2007 cm is randomly drawn on the number axis, an entire point will be covered by AB.

8. If m and n are reciprocal, then =;

︱3-? 8? 9︱+︱4-? 8? 9︱=

9. completely

The sum of nonnegative integers with a value less than 4 is equal to.

Three. Calculation questions (3 points for each question, ***2 1 point)

1.(-28)-(-36)+(-4) 2.2-(-3)-5-∣-7∣

3.× (-8) 4。 ×

5.6.- 1+[ 1-( 1-0.6× 13 )]×[3-(-3)×(-4)]

7.

IV. Solving problems (4 points +4 points +4 points +5 points, ***2 1 point)

1. Snails climb from roots to trunk in the morning, and the height of the tree is 10 meter. Snails climbed 4 meters during the day and slipped 3 meters at night. Please think about how many days it will take a snail to climb to the top of the tree.

2. An engineering team starts from A, and the right side means+the left side means-. At the end of the day, the statistics are: +5, -7,-12, +8, -7,+19, -3, +4, and finally arrive at B. Answer the following questions: (unit: km)

(1) On which side of A is B, and what is the distance?

(2) If the consumption of gasoline is 0.25 liter per kilometer, how much will it cost in place B, 5 yuan?

3. If yes, find the value of 2x+5y+.

Figure (4) is a model made of iron wire. If you want to calculate how long the wire is used, how many sides should the model measure at least?

Figure (4)

5. It is known that the distance between the point M representing the number A and the point representing the number-1 on the number axis is 3, and the distance between the point N representing the number B and the point representing the number 2 is 4. Find the distance between two points m and n ..