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We have, 9 + (- 6)

Firstly,draw a number line, then, wemove 9 steps to the right of 0 and reach at 9. Now,wemove6 steps to thelen of9 [∴  -6 is a negative integer] and reach at 3, as shown in the above figure. Hence, 9 + (-6) = 3

10> 9 > 8 > 4> 1 > -2>-3

(a) We can write 100 m below sea level as -100 m, because below sea level represents '-' sign and above sea level represents '+' sign.
(b) We can write 25°C above 0°C temperature as + 25°C, because temperature above 0°C is denoted by '+' sign and temperature below 0°C is denoted by '-' sign.
(c) We can write 15°C below 0°C temperature as -15°C, because temperature above 0°C is denoted by '+' sign and temperature below 0°C is denoted by '-' sign.
(d) Every negative integer is less than zero and every positive integer is greater than zero. 
\(\therefore\)  Numbers less than 0 are -1, - 2, - 3, - 4, - 5...

We know that, on the number line, all numbers to the right of a are positive integers and all numbers to the left of a are negative integers.
Thus, representation of numbers on the number line is as follows:

(a) 8 steps to the left of zero is represented by - 8.
(b) 7 steps to the right of zero is represented by + 7.
(c) 11 steps to the right of zero is represented by + 11.
(d) 6 steps to the left of zero is represented by - 6.

No, there are no such integers, which are less than - 3 and greater than -1.

We know that, on the number line points to the right of zero are positive integers and points to the left of zero are negative integers. Also, if move from left to the right on the number line, then number increases and if we move from right to the left on the number line, the number decreases.
(a) If we compare two negative integers on the number line, then the number which is on right of the other number will be greater.
e.g.  
Here, we see that - 2 is on the right of - 3, so - 2 is greater and - 3 is smaller.
(b) If we compare two positive integers on the number line, then the number which is on right of the other number will be greater.
e.g.  
Here, we see that 3 is on right of the 1, so 3 is greater and 1 is smaller.
c) If we compare one positive and one negative integers on the number line, then the number which is on right of the other number will be. greater.
e.g. 
Here, we see that 2 is on right of the -1, so 2 is greater and -1 is smaller.

Let the six integers be 1, 2, -2, 3, -3 and 6.
Now, sum of the above integers
= 1+ 2 + (-2) + 3 + (-3) + 6
We can arrange the numbers, so that the positive integers and the negative integers are grouped together.
We have, 1+ 2 + 3 + 6 + (-2) + (-3) = 12 - 2 - 3 = 12 - 5 = 7 
Hence, required integers are 1, 2, -2, 3, -3 and 6.
Note There are infinite combinations exist.

Temperature at 7 : 00 am = + 6° C
It is given that, temperature increased by 4°C in first hour.
So, temperature at 8 : 00 am = +6°C + 4°C  = 10°C
Temperature decreased in second hour by 1°C.
So, the temperature at 9 : 00 am = 10°C - 1°C = 9°C

According to the rules of addition and subtraction of integers,
(a) 30 + (-50) + (-20) = 30 -(50 + 20) = 30 -70 = -40
(b) 40 + (-10) + (-15) = 40 -(10 + 15) = 40 - 25 = 15
(c) 45 - (-5) + 10 = 45 + 5 + 10 = 60
(d) 60 - 10 + 5 - (-5 ) = 60 + 5 + 5 - 10 = 70 -10 = 60
(e) 16 + (-13) + (-10) =16 -(13 + 10) =16 - 23 = -7
(f) 0 + 5 - (-6) + (-7) = 0 + 5 + 6 - 7 ⇒ 11 - 7 = 4

Given, integer is -20
Precedessor of -20 = -20 - 1 = -21
Successor of -21 = -21 + 1 = -20
 

0°C to 10°C = +10° C -4° C to 8° C = +12°C (max.)
-15°C to -8°C = +7°C -7°C to 0°C = +7°C

Suppose, we take two negative integers -2 and -3.
Now, -2 - (-3) = -2 + 3 = 1 and -3 - (-2) = -3 + 2 = -1
So, the sign of the result dedpends on the numerical value of the integers.

Temperature at A = -4° C
Temperature at B = -1° C
We know that, -4 < -1 So, A is cooler than B.

The integers lying between -10 and -16 are -11, -12, -13. -14 and -15.
So, the least integer is -15.

The integers lying between -7 and 6 are -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5. Whole number are 0, 1, 2, 3, 4 and 5.
\(\therefore\)  The number of whole numbers = 6

The integers lying between -2 and 2 are -1, 0 and 1. So, there are 3 integers.

The predecessor of -1 = -1 - 1 = -2
\(\therefore\)  The required predecessor is -2.

5 units to the right of 0 is +5.

We know that, all the negative integers are less than zero and they have '-' sign.