#### T1 - Number System Important Questions

7th Standard

Reg.No. :
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Maths

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. The temperature at 12 noon at a certain place was 18° above zero. If it decreases at the rate of 3° per hour at what time it would be 12° below zero?

(a)

12 mid night

(b)

12 noon

(c)

10 am

(d)

10 pm

2. (-10) + ( +7)=____

(a)

+3

(b)

-3

(c)

-17

(d)

+17

3. 20 + (-9) + (9)

(a)

20

(b)

29

(c)

11

(d)

38

4. Which property is illustrated by the equation:(5 x 2) + (5 x 5) = 5 x (2 + 5)

(a)

commutative

(b)

closure

(c)

distributive

(d)

associative

5. Which of the following does not represent an Integer?

(a)

0 ÷ (-7)

(b)

20 ÷ (−4)

(c)

(-9) ÷ 3

(d)

(12) ÷ 5

6. 5 x 1 = 5
7.  -(30) + ____ = 60

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90

8. Fill in the blanks
(i) - 80$\times$__ = -80

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1

9. _____$\times$ (-9) = -45

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5

10.  (−40) ÷____ = 40

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-1

11. 75 + (-25) = __

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50

12. 5 x 1 = 5
13. (-45) - (-8) = (-8) - (-45)

(a) True
(b) False
14. (-100) x 0 x 20 = 0

(a) True
(b) False
15. (−30) ÷ (−6) = −6

(a) True
(b) False
16. The product of two negative integers is a positive integer

(a) True
(b) False
17. (−90) + ( −30) = 60

(a) True
(b) False
18. 5 x 1 = 5
19. For any two integers 72 and 108, 72 +108 is an also an integer

20. (1)

Commutative property under multiplication.

21. For any three integers 68, 25 and 99
68 x( 25 + 99) = ( 68 x 25 ) + ( 68 x 9)

22. (2)

23. 0 + (−138) = (−138) = (−138)+0

24. (3)

25. For any two integers (−5) and 10
(−5) x 10 = 10 x (−5)

26. (4)

Distributive property of multiplication over addition

27. 1 x (-1098) = (–1098) = (–1098) x 1

28. (5)

Multiplicative identity

7 x 2 = 14
(i) 8 and –12 using number line
(ii) (–3) and (–5) using number line
(iii) (-100 + (-10)
(iv) 20 + (-72)
(v) 82 + (-75)
(vi) -48 + (-15)
(vii) -225 + (-63)

30. Kabilan was having 10 pencils with him. He gave 2 pencils to Senthil and 3 to Karthik. Next day his father gave him 6 more pencils, from that he gave 8 to his sister. How many pencils are left with him?

31. What number should be added to (–17) to get (–19)?

32. During summer, the level of the water in a pond decreases by 2 inches every week due to evaporation. What is the change in the level of the water over a period of 6 weeks?

33. If P = -15 and Q = 5 find (P-Q) + (P+Q)

34. Subtract 94860 from (-86945)

35. Divide (72) by 8

36. 2 x 3 = 6
37. Add the following integers using number line
(i) 10 and –15
(ii) –7 and –9

38. Find the missing integers
(i) 0 + (2345) =______
(ii) 23479 +  ______= 0

39. 2 x 5 = 10
40. (i) Subtract (−40) from 70
(ii) Subtract (-12) from (-20)

41. A shopkeeper earns a profit of Rs. 5 by selling one notebook and incurs a loss of Rs. 2 per pen while selling of his old stock. In a particular day he earns neither profit nor loss. If he sold 20 notebooks, how many pens did he sell?