Page 130 - Start Up Mathematics_6

Values and Life Skills

A fighter jet flying at an altitude of 5,000 m suddenly gains 4,000 m. Later it comes down
to a height of 2,000 m to avoid detection by the enemies’ radar. Find the height at which the
jet is finally flying. Also find the net change in the altitude of the jet. What are the symptoms
of high altitude sickness? How can you avoid them?

Some NCERT Textbook Questions

1. 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.
2. 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
3. Using the number line write the integer which is:

(a) 3 more than 5
(b) 5 more than –5
(c) 6 less than 2
(d) 3 less than –2

4. Find the sum:
(a) (–7) + (–9) + 4 + 16

(b) (37) + (–2) + (–65) + (–8)
5. Fill in the blanks with > , < or = sign.
(a) (–3) + (–6) _____ (–3) – (–6)
(b) (–21) – (–10) _____ (–31) – (–11)

(c) 45 – (–11) _____ 57 + (–4)
(d) (–25) – (–42) _____ (–42) – (–25)

Exemplar Problems

1. The predecessor of the integer –1 is:

(a) 0 (b) 2 (c) –2 (d) 1
2. Number of whole numbers lying between –5 and 5 is:
(a) 10 (b) 3 (c) 4 (d) 5

3. The greatest integer lying between –10 and –15 is:
(a) –10 (b) –11 (c) –15 (d) –14
4. Which of the following shows the maximum rise in temperature?

(a) 0° C to 10° C (b) –4° C to 8° C (c) –15° C to –8° C (d) –7° C to 0°C

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