# 10 - Year 9 Assessment (35-40 min) MCQ & Short Ans

1. Decimal (Base 10) is the only number system in the world.

FALSE

TRUE

2. The ancient Mayan civilisation used the following number system (see image below). This is a ___________________ number system. base 19

base 10

base 15

base 20

3. Binary is a __________ number system.

base 0 and 1

base 2

base 1

base 0

4. In Binary you can create any number in the world using ___________________.

just four digits, 0,1,2,3

just two digits, 0 and 1

just the number 0, which can be placed next to any other number

just ten digits, 0,1,2,3,4,5,6,7,8,9

5. Why do computers use Binary? (Why is it that Binary is the foundational language for computer science and computers?)

6. Convert the Denary (Decimal) number 3 into Binary. Use two bits in your answer. (1 mark)

7. Binary additon is similar in some ways but different from the sort of addition we do with decimal numbers. Using Binary addition what is 1+0? (1 mark)

8. In Binary addition what is 1+1? Write the result and mention what number is carried over as well. E.g. 1 carry 1. (2 marks)

9. In Binary addition what is 1+1+1? What goes in a) and what goes in b). Write your answer in this format: a=?, b=? (2 marks) 10. In the following example, what are the values of a and b? Write your answer in this format: a=?, b=? (1 mark) 11. In a bitmap image, it is possible to store letters in a table, where each letter represents a colour. Explain how a bitmap image is stored in a computer (2 marks)

12. Explain how reducing the number of colours in an image can reduce its file size. (2 marks)

13. If you want a greater range of colours and tones, it would be better to use 2 bits. A greater number of bits would result in blurring.

FALSE

TRUE

14. According to the following chart, using 3 bits would allow you ___________________. 3 x 2 colours = 12 colours

8 colours

12 colours

3 colours

15. In pixel __________, the term _____________ refers to the total number of count of pixels in an digital image

resolution

pixolatton

colour depth

colouration

16. Which of the following (types of image) is the image on the left likely to be? pixelo

graphic

bitmap

vector

17. What is the following Binary number in Decimal?
`10000000`

18. What is the following Binary number in Decimal?
`11111111`

129

356

200

255

19. Neriah has created a number system. In it, 0 = *; 1 = & and 2 = @. Her number system is a base 3 system. What is the following number in Decimal? **@?

20. Steve wishes to write the number 512 in Binary. How would he do so?

He would need to add at least twelve more bits to the left of the 256 place value

He would need to add 500 more bits to the right of the 1 to allow for this

By adding an extra bit to the left of the 256 place value

He would not be able to do this as the greatest number is 128

21. Convert the following Binary number into Decimal: 00001111

11

15

12

18

22. Convert the following Binary number into Decimal: 10001000

236

120

136

122

23. Convert the following Binary number into Decimal: 12309312

123

80

21

This is not a binary number

24. A base 3 number system would have:

three digits, 0,1 and 2

one digit - 3

four digits, 0,1,2,3

two digits, 0 and 3

25. The largest number that can be represented in four bits is:

8

15

3

4