## Monday, 2 April 2012

### Remember

1. Every positive integer is larger than every negative integer.
2. Zero is less than every positive integer.
3. Zero is larger than every negative integer.
4. Zero is neither a negative integer nor a positive integer.
5. Farther a number from zero on the right, larger is its value.

1. Write opposites of the following :
1. Increase in weight
2. 30 km north
3. 326 BC
4. Loss of Rs 700
5. 100 m above sea level
 Given Statements Opposite Statements Increase in weight 30 km north 326 BC Loss of Rs 700 100 m above sea level Decrease in weight 30 km south 326 A.D. Gain of Rs 700 100 m below sea level
2. Represent the following numbers as integers with appropriate signs.
1. An aeroplane is flying at a height two thousand metre above the ground.
2. A submarine is moving at a depth, eight hundred metre below the sea level.
3. A deposit of rupees two hundred.
4. Withdrawal of rupees seven hundred.
1. An aeroplane is flying at a height two thousand metre above the ground. ==> + 2000
2. A submarine is moving at a depth, eight hundred metre below the sea level. ==> – 800
3. A deposit of rupees two hundred. ==> + 200
4. Withdrawal of rupees seven hundred. ==> – 700
3. Represent the following numbers on a number line :
(a) + 5 (b) – 10 (c) + 8 (d) – 1 (e) – 6

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. Answer: (a) F (b) negative integer  (c) B → + 4, E → – 10  (d) E F  (e) D, C, B, A, O, H, G, F
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. Answer:

### integers Form

Siachin 10°C below 0°C– 10°C
Shimla 2°C below 0°C–2°C
Delhi 20°C above 0°C+ 20°C
Srinagar 5°C below 0°C – 5°C
(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.

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
(a) 9 is to the right of 2
(b) – 3 is to the right of -8
(c) 0 is to the right of -1
(d) 10 is to the right of -11
(e) 6 is to the right of -6
(f) 1  is to the right of -100
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
(a) – 6, – 5, – 4, – 3, – 2, – 1
(b) – 3,– 2, – 1, 0, 1, 2, 3
(c) – 14, – 13, – 12, – 11, – 10, – 9
(d) – 29, – 28, – 27, – 26, – 25, – 24
8. (a) Write four negative integers greater than – 20.
(b) Write four negative integers less than – 10.
Answer: (a) – 19, – 18, – 17, – 16 (b) – 11, – 12, – 13, – 14

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.
 (a) – 8 is to the right of – 10 on a number line. True (b) – 100 is to the right of – 50 on a number line. Flase (c) Smallest negative integer is – 1. True (d) – 26 is greater than – 25. Flase
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?