**Q.1 Write opposites of the following:**

**(a) Increase in weight **

**(b) 30 km north **

**(c) 80 m east**

**(d) Loss of Rs 700 **

**(e) 100 m above sea level**

**Ans: ****(a) **Decrease in weight

(b) 30 km south

(c) 80 m west (d) Profit of Rs 700

(e) 100 m below sea level

**Q.2. Represent the following numbers as integers with appropriate signs.**

**(a) An aeroplane is flying at a height two thousand metre above the ground.**

**(b) A submarine is moving at a depth, eight hundred metre below the sea level.**

**(c) A deposit of rupees two hundred.**

**(d) Withdrawal of rupees seven hundred.**

**Ans: ****(a) (**+) 2000 m

(b) (–) 800 m

(c) (+) Rs 200

(d) (–) Rs 700

**Q.3. Represent the following numbers on a number line:**

**(a) + 5 (b) – 10 (c) + 8 (d) – 1 (e) – 6**

**Ans:**

**Q.4. Adjacent figure is a vertical number line, representing integers. Observe it and locate the following points :**

**(a) If point D is + 8, then which point is – 8?**

**(b) Is point G a negative integer or a positive integer?**

**(c) Write integers for points B and E.**

**(d) Which point marked on this number line has the least value?**

**(e) Arrange all the points in decreasing order of value.**

**Ans: ****(a) **If point D is +8, then point F is -8

(b) Point G is a negative integer

(c) Point B = (+)4 and point E (–) 10

(d) The least value on this number line is point E as it represents – 10

(e) The points in decreasing order of value are D, C, B, A, O, H, G, F, E

**Q.5. Following is the list of temperatures of five places in India on a particular day of the year.**

**Place Temperature**

**Siachin 10°C below 0°C ……………..**

**Shimla 2°C below 0°C ……………..**

**Ahmedabad 30°C above 0°C ……………..**

**Delhi 20°C above 0°C ……………..**

**Srinagar 5°C below 0°C ……………..**

**(a) Write the temperatures of these places in the form of integers in the blank column.**

**(b) Following is the number line representing the temperature in degree Celsius.**

**Plot the name of the city against its temperature.**

**(c) Which is the coolest place?**

**(d) Write the names of the places where temperatures are above 10°C.**

**Ans:**

**(a) **Siachin (–) 10^{0} C

Shimla (–) 2^{0} C

Ahmedabad (+) 30^{0} C

Delhi (+) 20^{0} C

Srinagar (–) 5^{0} C

**(b)**

**(c)** Siachin is the coolest place

**(d)** Ahmedabad and Delhi are the places where the temperatures are above 10^{0}C

**Q.6. In each of the following pairs, which number is to the right of the other on the number line?**

**(a) 2, 9 (b) – 3, – 8 (c) 0, – 1**

**(d) – 11, 10 (e) – 6, 6 (f) 1, – 100**

**Ans:**

**(a) **9 is right to 2 on the number line because 9 > 2.

(b) – 3 is right to -8 on the number line because -3 > – 8.

(c) 0 is right to -1 on the number line because 0 > -1.

(d) 10 is right to -11 on the number line because 10 > -11.

(e) 6 is right to -6 on the number line because 6 > -6.

(f) 1 is right to -100 on the number line because 1 > -100.

**Q.7. Write all the integers between the given pairs (write them in the increasing order.)**

**(a) 0 and – 7 (b) – 4 and 4**

**(c) – 8 and – 15 (d) – 30 and – 23**

**Ans: ****(a) **-6, -5, -4, -3, -2, -1 are the integers between 0 and -7

(b) -3, -2, -1, 0, 1, 2, 3 are the integers between -4 and 4

(c) -14, -13, -12, -11, -10, -9 are the integers between -8 and -15

(d) -29, -28, -27, -26, -25, -24 are the integers between -30 and -23

**Q.8. (a) Write four negative integers greater than – 20.**

**(b) Write four integers less than – 10.**

**Ans: ****(a) **-19, -18, -17, -16 are the integers greater then -20

(b) -11, -12, -13, -14 are the integers less than -10

**Q.9. For the following statements, write True (T) or False (F). If the statement is false, correct the statement.**

**(a) – 8 is to the right of – 10 on a number line.**

**(b) – 100 is to the right of – 50 on a number line.**

**(c) Smallest negative integer is – 1.**

**(d) – 26 is greater than – 25.**

**Ans: ****(a) **True as because -8 > -10

(b) False. Because -50 is greater than -100. Hence, -100 lies to the left of -50 on the number line.

(c) False. -1 is the greater negative integer.

(d) False. -26 is smaller than -25

**Q.10. Draw a number line and answer the following:**

**(a) Which number will we reach if we move 4 numbers to the right of – 2.**

**(b) Which number will we reach if we move 5 numbers to the left of 1.**

**(c) If we are at – 8 on the number line, in which direction should we move to reach – 13?**

**(d) If we are at – 6 on the number line, in which direction should we move to reach – 1?**

**Ans:**