Tuesday 3 April 2012

CBSE Class 6th ( VI) Mathematics Chapter 6. Integers: Exercise 6.3

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.
  6. whole numbers and the negative numbers together form a collection of numbers know as Integers
  7. -3, -2, -1, 0, 1, 2, 3 Are all Integers
  8. 1, 2, 3, ... are said to be positive integers and – 1, – 2, – 3,.... are said to be negative integers
  9. You add when you have two positive numbers like (+3) + (+2) = +5 [= 3 + 2].
  10. You also add when you have two negative numbers, but the answer will take a minus (–) sign like (–2) + (–1) = – (2+1) = –3.
  11. when you have one positive and one negative integer, you must subtract, but answer will take the sign of the bigger integer (Ignoring the signs of the numbers decide which is bigger)
  12. to subtract an integer from another integer it is enough to add the additive inverse of the integer that is being subtracted, to the other integer. (– 3) – (+ 3) = (– 3) + (additive inverse of + 3) = (– 3) + (– 3) = – 6
1. Find
  1. 35 – (20)
  2. 72 – (90)
  3. (– 15) – (– 18)
  4. (–20) – (13)
  5. 23 – (– 12)
  6. (–32) – (– 40)
Answer:
(a) 35 – (20) = 15
(b) 72 – (90) = – 18
(c) (– 15) – (– 18) = 3
(d) (–20) – (13)= – 33
(e) 23 – (– 12) = 35
(f) (–32) – (– 40)= 8
2. Fill in the blanks with >, < or = sign.
  1. (– 3) + (– 6) ______ (– 3) – (– 6)
  2. (– 21) – (– 10) _____ (– 31) + (– 11)
  3. 45 – (– 11) ______ 57 + (– 4)
  4. (– 25) – (– 42) _____ (– 42) – (– 25)
Answer:
  1. (– 3) + (– 6) < (– 3) – (– 6)
  2. (– 21) – (– 10) > (– 31) + (– 11)
  3. 45 – (– 11) > 57 + (– 4)
  4. (– 25) – (– 42) > (– 42) – (– 25)
3. Fill in the blanks.
  1. (– 8) + _____ = 0
  2. 13 + _____ = 0
  3. 12 + (– 12) = _____
  4. (– 4) + _____ = – 12
  5. _____ – 15 = – 10
Answer:
  1. (– 8) + 8 = 0
  2. 13 + -13 = 0
  3. 12 + (– 12) = 0
  4. (– 4) + -8 = – 12
  5. 5 – 15 = – 10
4. Find
  1. (– 7) – 8 – (– 25)
  2. (– 13) + 32 – 8 – 1
  3. (– 7) + (– 8) + (– 90)
  4. 50 – (– 40) – (– 2)
Answer:
(a)(– 7) – 8 – (– 25)= 10
(b) (– 13) + 32 – 8 – 1= 10
(c)(– 7) + (– 8) + (– 90)= -105
(d)50 – (– 40) – (– 2)= 92

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