2. It is correct to round 3. 14 15926 to one thousandth. If 302400 is expressed by scientific notation, it should be recorded as about 3.0× accurate to one decimal place.
3. It is known that the circumference of a circle is 50, and the radius of the circle is expressed by an algebraic expression containing π, which should be.
4. Each pencil is worth 1000000 yuan. After Xiao Ming bought n pencils with10 yuan, there was still RMB left.
5. When a =-2, the value of algebraic expression is equal to.
6. The algebraic expression 2x3Y2+3x2Y- 1 is a second-order term.
7. If 4amb2 and abn are similar terms, then m+n=.
8. Polynomials 3x3y- xy3+x2y2+y4+Y4 are arranged in ascending order by the letter X.
9. If it is ∣x-2∣= 1, then it is ∣x- 1∣=.
10, calculation: (a- 1)-(3a2-2a+ 1) =.
1 1. Calculate with a calculator (keep 3 significant figures): =.
12, Blackjack Game: Use the following numbers to score 24 points (each number can only be used once).
2, 6, 7, 8. Formula.
13, calculation: (-2a)3 =.
14, calculation: (x2+x- 1)? 6? 1(-2x)= .
15. Observe the rule and calculate: (2+1) (22+1) (24+1) (28+1) =. The calculator doesn't work, and the result is in the form of power. )
Second, the choice (this big topic * * * a total of 4 questions, each question 2 points, out of 8 points)
16, the following statement is correct .................................................. ()
(A)2 is not algebraic; (b) it is a single item.
The linear coefficient of (c) is 1 (D) 1 is a monomial.
17. The following merged similar projects are correct ....................................................................... ()
(A)2a+3a = 5(B)2a-3a =-A(C)2a+3b = 5ab(D)3a-2b = ab
18, the following set of numbers arranged according to the law: 1, 2, 4, 8, 16, ..., No.2002 should be ().
A, b,-1 C, d, the above answers are incorrect.
19. If we know that A and B are reciprocal, and X and Y are reciprocal, then algebraic expression.
The value of |a+b|-2xy is ().
A.0b-2 c.-1d. cannot be determined.
Iii. Answer: (This big question is * * *, with a total of 4 questions, with 6 points for each question, out of 24 points).
20. Calculation: x+ +5
2 1, evaluation: (x+2) (x-2) (x2+4)-(x2-2) 2, where x =-
(3) By (1), (2) What did you find or think of?
23. Given that a = 2x2-x+ 1, a-2b = x- 1, find b.
Four, the application problem (this big problem * * * has five questions, 24, 25 each question 7 points, 26, 27, 28 each question 8 points, out of 38 points)
26. It is understood that the taxi charging standards in our city are as follows: if the mileage does not exceed five kilometers, 5 yuan will be charged; If the mileage exceeds 5 kilometers, the excess part will be charged at 1.2 yuan per kilometer except 5 yuan.
(1) If someone travels by taxi for x kilometers (x >: 5), how much should he pay? (Column Algebra) (4 points)
(2) A tourist takes a taxi from Xinghua to Shagou and pays 4 1 yuan. Try to estimate how many kilometers it is from Xinghua to Shagou. (4 points)
27, the members of the first team and the second team get together. There are m people in the first team, and the second team has two more people than the first team. If each member of two teams gives a gift to each member of the other team.
Q: (1) The total number of gifts given by all players. (represented by the algebraic expression of m)
(2) When m= 10, how many gifts are given?
28. The price of a commodity in 1998 is 5% higher than that in 1997, while the price in 1999 is higher than that in 1998, and the price in 2000 was lower than that in 1999. So, in 2000, compared with 1997, was it price increase or price decrease? What is the percentage of price increase or decrease?
29. The runners on the playground ran a 400-meter-long lap. A practiced riding a bike, riding an average of 350 meters per minute; B practice running, running an average of 250 meters per minute. How long does it take for two people to meet for the first time from the same place and in the opposite direction at the same time? How long did it take to meet again?
Junior high school first semester math test paper (experimental class)
I. Fill in the blanks (1 each blank, 30 * * *)
The reciprocal of 1,-1( 1/2) is _ _ _ _, the opposite number is _ _ _ _ _ _, and the absolute value is _ _ _ _ _.
2. Write down 690000 = _ _ _ _ _ _ with scientific notation.
3. The algebraic expression a2+b2 represents _ _ _ _ _ _ _ _ _ _ _.
4、0÷(-3)=_______,3. 14×(- 18.9)×0×(- 1)=_________。
5. 24000 is accurate to _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
6. The number represented by a point two units long from the origin on the number axis is _ _ _ _.
7. The algebraic expression indicates that the output will increase from X kg 10% to _ _ _ _ kg.
8. Contrast size: |-3 | _ _ π,-2/3 _-3/4, 0.32 _ _-0.33.
9.- 1 1 is _ _ larger than -9, and simplified-[+(-5)] = _ _ _ _.
10, one of the three consecutive integers is n+ 1, and the other two are _ _ _ _ _ _ _ _.
1 1, if |x|=0.2, then x=____, and 0.0984 retains two significant digits around _ _ _ _.
Integers whose absolute value is 12 and less than 3 are _ _ _ _ _ _ _ _ _, their sum is _ _ _ _ _ _ _, and their product is _ _ _ _ _ _ _ _.
13, if 2.4682=6.09 1, then () 2 = 0.069 1.
The reciprocal of 14 and _ _ _ _ _ _ _ is equal to its square.
The maximum values of 15 and 5-a2 are _ _ _ _ _ _ _.
16, if 3 is the reciprocal of y, then 3y2 = _ _ _ _ _ _
The reciprocal of the sum of 17,115 and 2/ 15 is _ _ _ _.
18, if |a|+a=0, then a _ _ _ _ 0.
19，if (2x- 1)2+|y-3|=0，2x-y = _ _ _ _ _。
20. If A and B are antonyms, C and D are reciprocal, and |m|=2, then A+B/A+B+C+M2-CD = _ _ _.
Second, true or false questions (each question 1 point, * * *1point)
1, when n=5, the value of algebraic expression 2n+ 10 is 20, so the value of algebraic expression 2n+ 10 is always 20. ( )
2, -5.88 is negative. ( )
3. All rational numbers can be represented by points on the number axis. ( )
Subtracting a number is equal to adding the reciprocal of this number. ( )
5. Rational numbers include positive rational numbers and negative rational numbers. ( )
6. I know, x>0, y<0 and | x | < |y| and then X+Y >; 0。 ( )
7. The quotient of two numbers with opposite numbers must be equal to-1. ( )
8. When n is a natural number, (-1) 2n-1+(-1) 2n = 0. ( )
9. If |a|=2, |b|=5, ab >；; 0 means a-b=-3. ( )
10, if x>y, then x2 & gty2. ()
Three, multiple-choice questions (2 points per question, ***20 points)
1, the following is not algebra ()
a、0 B、3+4=7 C、π D 、( a+b)/2
2. The condition of having the number of axes is ()
a、—┴—┴—┴—→ B、——┴——→ C、—┴—┴—┴— D、—┴——┴—→
- 1 0 1 0 - 1 0 1 - 1 1
3. Comparing the sizes of -32 and (-23), the correct one is ().
A, -32 >(-2)3 B, -32=(-2)3 C,-32 < (-2) 3d, which can't be compared.
4.-|-a| is a ()
A, positive B, negative C, positive or zero D, negative or zero
5. Let A be the smallest natural number, B be the largest negative integer and C be the smallest absolute rational number, then the sum of A, B and C is ().
A,-1 B, 0 C, 1 D, does not exist.
6, the following proposition, the correct is ()
A, the opposite number is only equal to your own number 0; B, the number whose reciprocal equals itself is only1;
C, the number whose square equals itself is+1, 0,-1; D, the number whose absolute value is equal to itself is only 0 and 1.
7, the product of rational number and its inverse is ()
A, the symbol must be positive B, the symbol must be negative C, and it must be not greater than zero D and not less than zero.
8. Rational number A should be () relative to1/a.
a、a & gt 1/a B、a & lt 1/a C、a≠ 1/a D、a & gt 1，a & gt 1/a
9. The corresponding points of rational numbers A, B and C on the number axis are shown in the figure below, and the correct one in the following formula is ().
———┴———┴—┴——┴————→
FOB
A. ac< BC & nbspb, A+B+C < 0 C、a+b+ C & gt； 0 D, bc> abdominal muscles
10, the following median must be positive ()
a 、|a|+|b| B、a2+b2 C、a2+ 1 C、a
4. Calculation: (1, 3 points for 2 questions, 4 points for 3 questions, 4 points for 4, 5, 6 and 3 questions. ***22 points)
( 1) 1/3- 1/2-3/4+2/3 (2)-8/9×0.25×(- 1/4)÷ 1/9
(3)99(99/ 100)×(- 100) (4)3×(-2.5)×(-4)+5×(-6)×(-3)2
(5)[-3+(-5+|-4|)×(-3/2)]÷3/2÷(-3/2)3 (6)- 14-( 1-0.5)× 1/3×[2-(-3)2]
Verb (the abbreviation of verb) finds the algebraic value (5 points for each question, *** 10).
1, when x=-2, find the algebraic expression-(1/2) x2+1/3x-1/6.
2. It is known that when (m+n)/(m-n)= 1/3, the value of (m-n)/(m+n)-3(m+n)/(m-n) is found.
No answer