EXERCISE 6.1

**1) Write opposites of the following :**

**(a) Increase in weight.**

**Ans:** Decrease in weight.

**(b) 30 km north.**

**Ans:** 30 km south.

**(c) 326 BC.**

**Ans:** 326 AD.

**(d) Loss of Rs.700.**

**Ans:** Profit of Rs.700.

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

**Ans:** 100 below sea level.

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

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

**the ground.**

**Ans:** + 2000.

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

**the sea level.**

**Ans:** – 800.

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

**Ans:** + 200.

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

**Ans:** – 700.

**3) Represent the following numbers on a number line :**

**(a) + 5**

**Ans:**

**(b) -10**

**Ans :**

**(c) +8**

**Ans:**

**(d) -1**

**Ans:**

**(e) -6**

**Ans:**

**4) Adjacent 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?**

**Ans:** F.

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

**Ans:** Negative integer.

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

**Ans:** B = +4 , E = −10.

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

**Ans**: E.

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

**Ans:** D, C, B, A, O, H, G, F, E.

**5) Following is the list of temperature of five places in India, on a particular day of the year.**

Place |
Temperature |

Saichin |
10˚ C below 0˚ |

Shimla |
2˚ C below 0˚ |

Ahmedabad |
30˚ C below 0˚ |

Delhi |
20˚ C below 0˚ |

Srinagar |
5˚ C below 0˚ |

**(a) Write the temperature of these place in the form of integers in**

**the blank column.**

**Ans:** -10˚ C, −2˚ C, +30˚ C, +20˚ C, −5˚ C.

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

**degree Celsius.**

**Ans:**

**(c) Plot the name of the city against its temperature.**

**Which is the coolest place?**

**Ans:** Siachin.

**(d) Write the name of the places whose temperature are above**

**10˚C .**

**Ans:** Delhi and Ahmedabad.

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

**(a) 2, 9 ****Ans:** 9.

**(b) −3, −8 ****Ans:** −3.

**(c) 0, −1 ****Ans:** 0

**(d) −11, 10 ****Ans:** 10.

**(e) −6, 6 ****Ans:** 6

**(f) 1, −100 ****Ans:** 1.

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

**(a) 0 and −7.**

**Ans:** −6, −5,−4,−3,−2,−1.

**(b) −4 and 4.**

**Ans:** −3, −2, −1, 0, 1, 2, 3.

**(c) −8 and −15.**

**Ans:** −14, −13, −12, −11, −10, −9.

**(d) −30 and −23.**

**Ans:** −29, −28, −27, −26, −25, −24.

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

**Ans:**−10, −11, −12, −13.

**(b) Write four negative integer less than -10.**

**Ans:**−14, −15, −16, −17.

**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.**

**Ans:** True.

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

**Ans:** False, −100 is to the left of −50 on a number line.

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

**Ans:** False, greatest negative integer is −1.

**(d) −26 is larger than −25.**

**Ans:** False, −26 is smaller than −25.

**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.**

**Ans:** +2

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

**Ans:** -4.

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

**Ans:** Since −13 lies to the left at −8, we should move towards left.

**(d) If we are at −6on the number line in which direction should we**

**move to reach −1?**

**Ans:** Since −1 lies to right of −6 on the number line, we should move towards right direction.