Eight practical questions of positive and negative numbers in the first day of junior high school Want 8 addition and subtraction application problem, positive and negative number! Right now!

1. Multiple choice questions:
(1) Write - 2 - (+ 3) - (- 5) + (- 4) + (+ 3) in the form of omitting the sum of brackets
A．-2-3-5-4+3 B．-2+3+5-4+3
C．-2-3+5-4+3 D．-2-3-5+4+3
(2) The correct result of (- 5) - (+ 3) + (- 9) - (- 7) + is ()
A．-10 B．-9 C．8 D．-23
(3) The algebraic sums of - 7, - 12, + 2 are smaller than the sum of their absolute values ()
A．-38 B．-4 C．4 D．38
(4) If + (B + 3) 2 = 0, then the value of B-A - is ()
A．-4 B．-2 C．-1 D．1
(5) The following statement is correct ()
A. Subtracting two negative numbers is equal to subtracting the absolute value
B. The difference between two negative numbers must be greater than zero
C. Positive minus negative is actually the algebraic sum of two positive numbers
D. Negative minus positive equals the absolute value of negative plus positive
(6) Formula - 3-5 cannot be read as ()
A. The difference between - 3 and 5 B. the sum of - 3 and - 5
C. The difference between - 3 and - 5 d. - 3 minus 5
2. Fill in the blanks: (4 ′× 4 = 16 ′)
（1）-4+7-9=- - + ；
（2）6-11+4+2=- + - + ；
（3）（-5）+（+8）-（+2）-（-3）= + - + ；
（4）5-（-3 ）-（+7）-2 =5+ - - + - .
3. Write the following forms in the form of sum with brackets omitted, and give two ways to read them: (8 ′× 2 = 16 ′)
（1）（-21）+（+16）-（-13）-（+7）+（-6）；
（2）-2 -（- ）+（-0.5）+(+2)-(+ )-2.
4. Calculation (6 ′× 4 = 24 ′)
(1)-1+2-3+4-5+6-7;
(2)-50-28+(-24)-(-22);
(3)-19.8-(-20.3)-(+20.2)-10.8;
(4)0.25- +(-1 )-(+3 ).
5. When x = - 3.7, y = - 1.8, z = - 1.5, find the value of the following algebraic formula (5 ′× 4 = 20 ′)
(1)x+y-z; (2)-x-y+z; (3)-x+y+z; (4)x-y-z.
[quality optimization training]
(1) (-7)-(+5)+(+3)-(-9)=-7 5 3 9;
(2)-(+2 )-(-1 )-(+3 )+(- )
=( 2 )+( 1 )+( 3 )+( );
(3)-14 5 (-3)=-12;
(4)-12 (-7) (-5) (-6)=-16;
(5)b-a-(+c)+(-d)= a b c d;
2. When x =, y = - and z = - the values of the following algebraic expressions are obtained respectively;
(1)x-(-y)+(-z); (2)x+(-y)-(+z);
(3)-(-x)-y+z; (4)-x-(-y)+z.
3. Verify the equation for the following three groups of numbers:
Whether a - (B-C + D) = A-B + C-D holds
(1)a=-2,b=-1,c=3,d=5;
(2)a=23 ,b=-8,c=-1 ,d=1 .
4. Calculation
(1)-1-23.33-(+76.76);
(2)1-2*2*2*2;
(3)(-6-24.3)-(-12+9.1)+(0-2.1);
(4)-1+8-7
[practical application in daily life]
On the first day, a water conservancy survey team walked 5 kilometers upstream, 5 kilometers upstream on the second day, 4 kilometers downstream on the third day, and 4.5 kilometers downstream on the fourth day. Where is the starting point of the survey team? How many kilometers apart?
Reference answer:
[synchronized practice]
1.(1)C;(2)B;(3)D;(4)A;(5)C;(6)C 2.(1)4,(-7),(-9) (2)(-6),(-11),(-4),2; (3)-5,8,2,3; (4)3,7,2;
(1) - 4; (2) - 80; (3) - 30.5 (4) - 5
5.(1)-4; (2)4; (3)0.4; (4)-0.4.
[quality optimization training]
1.(1)-,+,+; (2)-,+,-,-; (3)+,+; (4)-,+,+; (5)-,+,-,-.
2.(1) (2) (3) (4)-
3. (1) (2) all hold water
4.(1)-
(2)
(3)-29.5
(4) Note that numbers with the same sign and numbers opposite to each other should be combined first

Analysis of positive and negative numbers in 100 calculation questions
The addition of 50 positive and negative numbers and the subtraction of 50 positive and negative numbers

1. The number in life, which is larger than "0", is called______ A number smaller than "0" is called a number____ The number "0" is neither positive nor negative
We can express it with positive and negative numbers________________________ The amount of money
3. If - 30 is 30 yuan, then + 200 is 30 yuan___________________________
4. If the water level in the river is 0.2 m lower than the normal water level, it is recorded as - 0.2 m, then it is 0.5 m higher than the normal water level
Record as_________________________
5. An object can move left and right, 12 m to the left, denoted as - 12 m and 8 m to the left____ Mobile_____ m.
6. The highest Mount Qomolangma in the world is 8848m higher than the sea level. If this height is expressed as 8848m, then the height of Turpan Basin in Xinjiang, which is 155m lower than the sea level, should be expressed as 8848m________ M; the height of the sea level is_______ Rice
7. If Xiaohua's monthly income of 2500 yuan is recorded as 2500 yuan, then his monthly expenditure on water, electricity and gas of 200 yuan should be recorded as 2500 yuan________ Yuan
8. If the elevator goes up 15 floors, it is recorded as 15 floors, then it goes down 6 floors, it is recorded as 15 floors_______ Layer
9. If 3 goals are recorded as 3, then 2 goals should be recorded as 3_________
10. The temperature at 12:00 noon is 7 ℃, the temperature at 5:00 pm is 4 ℃ lower than that at 12:00 noon, the temperature at 4:00 am is 8 ℃ lower than that at 12:00 noon, and the temperature at 5:00 pm is 8 ℃____ What's the temperature at 4 a.m_____ .
11. Please record Xiaoming's income and expenditure with positive and negative numbers in the form
On May 4, Dad's salary of 1500 yuan was recorded as:_____________
On May 6, the expenditure of 200 yuan on water, electricity and gas was recorded as:_____________
On May 12, the telephone fee of 120 yuan was recorded as:_____________
On May 15, my mother's salary of 1400 yuan was recorded as:_____________
12. The factory produces a batch of parts, the diameter of which is required to be 40mm. Now the inspector has inspected 10 of them, and the inspection results are as follows: (unit: mm)
39.7 40 40.1 39.9 40 40.3 39.8 40.2 40.1 39.9
If the standard is 40mm, the excess part is positive and the deficiency part is negative, the 10 parts can be recorded as follows:_____________________________________________________________
1. Complete the form below
The following table shows the daily temperature changes in different parts of the country: (unit: ℃)
City Shenzhen Guangzhou Tianjin Shanghai Jiangxi Harbin
The highest temperature is 20 22 8 59 - 1
Minimum temperature 15 16 - 3 - 1 3 - 13
Temperature difference
2. There are the following words on the package of some bagged food in a supermarket in Nanshan District: Net Content: 500ml ± 10ml______________________________________________________
The results are as follows: (unit: ML)
1 2 3 4 5 6 7 8 9 10
Content 490 503 510 498 509 504 499 492 504 491
More (less) than net content ML - 10 + 3
What does the table show_____________________________________________________
The total content of these ten bags of food is as follows:_____________ ml.
3. There are several people on the bus (the number of people getting on the bus is positive, the number of people getting off the bus is negative)
-Five, three, five, eight, - 10, six, four, - seven, - three, two,
After ten stops, how many people are there on the bus____________________________
（50-59+92）+15
30/5+64*9-62/12
32+69-458
2159+1151-9584 51206+849+9-8948
951*59+594-694*45+18-484 651/3-8451/9-69+458
1254+9-45-（-45）*569
5264*9548*（-65）*（-569）/3
529*462*4658+695+（+265）+（-569）

There are positive numbers and negative numbers from A1 to F1. The sum of positive numbers and negative numbers in A1 to F1 is expressed by formulas respectively

=SUMIF(A1:F1,">0",A1:F1)
=SUMIF(A1:F1,"

There are positive and negative values in one row of a table. Add positive and positive values, and add negative and negative values to find the formula

=SUMPRODUCT(IF(A1:G1>0,A1:G1))
After input, do not enter, but press Ctrl + Shift + enter
This is the sum of the positive numbers in A1: G1
=SUMPRODUCT(IF(A1:G1

How to add and subtract negative numbers

A negative number is actually a positive number plus a negative sign. It's the same as a positive number. You can put forward a negative sign and then operate

Mixed operation of addition, subtraction, multiplication and division with negative number, positive number and power
15 is OK, SOS

[-|98|+76+(-87)]*23[56+(-75)-(7)]-(8+4+3) 5+21*8/2-6-59 68/21-8-11*8+61 -2/9-7/9-56 4.6-(-3/4+1.6-4-3/4) 1/2+3+5/6-7/12 [2/3-4-1/4*(-0.4)]/1/3+2 22+(-4)+(-2)+4*3 -2*8-8*1/2+8/1/8 (2/3+1/2)/(-1/12)*(-1...

Why do negative minus negative sometimes get positive and sometimes negative
Rational number addition and subtraction method a little dizzy, help to solve, a little forgotten
Negative number plus negative number - 15 + (- 5) =
Minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus minus
Negative plus positive - 23 + 2 = -
Negative minus positive - 6 - (15) =
Positive minus negative 20 - (- 15) =
Don't just do these questions, but also tell me the method
In particular, negative minus negative and negative plus positive seem to have two answers

Negative plus negative - 15 + (- 5) = - 15-5 = - 20
Negative minus negative - 16 - (- 7) = - 16 + 7 = - 9
Negative plus positive - 23 + 2 = - 21
Negative minus positive - 6 - (15) = - 6-15 = - 21
Positive minus negative 20 - (- 15) = 20 + 15 = 35

A negative number minus a larger positive number, the result is positive or negative?

Negative number

A negative number minus a larger positive number, the result is positive or negative? Why?

The result is negative
Because the opposite number of a positive number is negative, subtracting a positive number is adding the opposite number of the positive number, so it becomes a negative number plus a negative number, so the result is still negative

What number is a negative number multiplied by a negative number? What number is a negative number minus a negative number!

A negative number multiplied by a negative number is a positive number
Negative minus negative is a number with larger absolute value

Eight practical questions of positive and negative numbers in the first day of junior high school Want 8 addition and subtraction application problem, positive and negative number! Right now!