Page 118 - Start Up Mathematics_6

(c) Zero is greater than every negative integer.

(d) Zero is neither a negative integer nor a positive integer.
(e) Farther a number is to the right of zero, larger is its value.

(f) Farther a number is to the left of zero, smaller is its value.
Example 1: Write the opposites of the following:

(a) Increase in weight (b) 50 km west (c) 305 AD
(d) Profit of ` 300 (e) 120 m above sea level
Solution: (a) Decrease in weight (b) 50 km east (c) 305 BC

(d) Loss of ` 300 (e) 120 m below sea level
Example 2: Represent the following numbers as integers with appropriate signs.

(a) An aeroplane is flying at a height of three thousand metres above the ground.
(b) A submarine is moving at a depth of eight hundred metres below the sea level.

(c) A deposit of two thousand rupees
(d) A withdrawal of two hundred rupees

Solution: (a) +3,000 (b) –800 (c) +2,000 (d) –200
Example 3: Represent the following integers on a number line:
(a) +9 (b) –10 (c) +7 (d) 0

Solution: The integers in part (a), (b), (c) and (d) are represented by letters A, B, C and D
respectively.

B D C A

–10 –9 –8 –7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7 8 9 10

Example 4: The adjacent figure is a vertical number line representing
integers. Locate the following points: D
(a) If point A is +2, then which point is –2? C

(b) Is point F a negative integer or a positive integer?
(c) Write integers for B and G. B
A +2
(d) Which point marked on this number line has the least value?
O 0
(e) Arrange all the points in ascending order of value.
E
(f) Which integer is opposite to D?
Solution: (a) –2 is represented by point E F

(b) Negative Integer G
(c) B = +3, G = –6 H

(d) H = –9 has the least value

(e) H < G < F < E < O < A < B < C < D
(f) The integer opposite to D is H.

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