1 is the sum of two numbers with opposite numbers (0); The product of two reciprocal is (1).
If the absolute value of a number is 2, then the number is (plus or minus 2).
Two points A and B on the 3-number axis represent -3 and 1 respectively, so the distance between A and B is (4).
If the product of four unequal integers is equal to 9, then the sum of the absolute values of these four integers is (8).
5 Write five rational numbers (including three points) whose product is-1. ( 1,- 1)(0.5,-2) (0.2, -5)
6 Rounding off the divisor of 5978.4 (with two significant figures reserved) is (6.0 * 10 3).
There are (4) integers, where 7 is greater than -2.7 and less than 1.6.
8 Fill in the following rational numbers in the corresponding set:
-3 is 1/2,0, -7.25,+12, 3 is1/2, |-5|, -4, -(- 1/3).
PS:-3 and 1/2 = negative three and a half.
Integer set: {0+12 |-5| -4}
Negative integer set: {-4}
Score set: {-31/231/2-(-1/3)}
Negative sets: {-3 and1/2-7.25-4-(-1/3)}
9, put the numbers -3 and1/2,0,1/2,3, -0.5.
From small to large: (-3 and 1/2
10 calculation. Write a calculation process
(1)9 and 1/2 X 1 and 3/4 ÷ (- 19)+ 19:
= 19/2*7/4* 1/ 19+ 19
=7/8+ 19
= 19 7/8
(2)25 ÷ (-5) ÷ ( 1/5 )
=-25* 1/5*5
=-25
1 1. Formula calculation:
1 is smaller than the reciprocal of -2. The difference between the square of 5:2-2 and the product of -2 and -4:
-(-2)-5=-3 (-2)^2-(-2)*(-4)
=4-8=-4
12. A fruit shop bought 10 baskets of apples from the orchard, and each basket was 50 kg. If it exceeds the standard, it will be recorded as positive, and if it fails to meet the standard, it will be recorded as negative. Now use the following formula (unit: kg) to calculate.
+ 1,+ 1.5,-0.8,-2,0,+ 1.2,-0.5,- 1,0,+2.
(1) How many Jin of apples did this fruit shop buy?
1+ 1.5-0.8-2+0+ 1.2-0.5- 1+0 = 1.4kg。
50+1.4 = 51.4kg.
(2) The price tag of the fruit shop says that the unit price of apples is 4 yuan/Jin, and the preferential price is 3.5 yuan/Jin. If the purchase price of apples in this fruit shop is 2 yuan/Jin, * * * will make a profit when all the apples purchased by this fruit shop are sold out.
how much is it?
(3.5-2)*5 1.4=77. 1 kg
(13). Students in Class 3, Grade 7 play checkers. The rules of the game are as follows: first draw a number axis, and the flag falls on K0 on the number axis. The first step is to jump from point K0 to point K 1 a unit length, the second step is to jump from point K 1 by two units to the right, and the third step is to jump from point K2 by three units to the left. Step 4: Jump from point K3 to point K4 by 4 unit lengths ... So jump 20 steps and the flag will fall to point K20 on the number axis. If the number represented by point K20 is 18, what is the number represented by point K0? How to get the result, the process.
K0- 1+2-3+4-...- 19+20 = 18.
k0- 1+2-3+4-……- 19+20
= k0+2- 1+4-3+……+20- 19
=k0+ 1+……+ 1
=k0+ 10= 18
K0=8