# vs.eyeandcontacts.com

## Chapter 1 Number System

Brain Developers
A. Fill in the blanks:
1. The base of Binary number system is 2.
2. The base of decimal number system is 10.
3. Octal number system consists of 8 digits.
4. In Binary addition, 1 + 1 equals to 10.
5. Binary number system is understood by the computer system.
6. Hexadecimal number system uses 16 digits, from 0 to 9 and letters A to F.
7. In Binary subtraction, 1 - 1 equals to 0.

B. State True or False:
1. You cannot perform arithmetical operations on binary numbers. (False)
You can perform arithmetical operations on binary numbers.
2. The decimal number system consists of 10 digits, i.e., 0 to 9. (True)
3. The method to perform division of two binary numbers is not the same as that of decimal numbers. (False)
The method to perform division of two binary numbers is the same as that of decimal numbers.
4. 1 multiplied by 0 equals to 0. (True)
5. Charles Babbage introduced the concept of 0 (Zero). (False)
Aryabhat introduced the concept of 0 (Zero).
6. The numbers used in Octal number system are 1 to 7. (False)
The numbers used in Octal number system are 0 to 7.

C. Application Based Questions:
1. Ratika's computer teacher asked her to convert the Octal number to Decimal number. Suggest her the method which she should apply in converting the Octal number.
Multiply each octal number with 8 having the power 0 for unitary position, starting from the extreme right digit.

2. The teacher has given as assignment to Saurabh on Binary subtraction. Saurabh is confused how to subtract 1 from 0. Help him solving the problem.
He can solve this by borrow method as (0 - 1 = 1).

D. Multiple Choice Questions:
1. _____________ introduced the concept of 0 (Zero).
b) Aryabhat
c) Charles Babbage
b) Aryabhat

2. A __________ converts the decimal format into its binary equivalent.
a) Digital Computer
b) Cell Phone
c) Abacus
a) Digital Computer

3. A computer understands only the ___________ code.
a) English
b) French
c) Binary
c) Binary

4. In Binary multiplication, 1 × 1 equals to ____________.
a) 0
b) 1
c) 2
b) 1

5. To convert a Decimal number into a Binary number, divide the number by _____________.
a) 2
b) 8
c) 10
a) 2

1. What is a number system? Explain its commonly used types.
There are four different types of number system -
a) Binary number system
b) Octal number system
c) Decimal number system

2. What are the rules to convert a Decimal number into a Binary number?

Step 1: Divide the given decimal number with the base 2.
Step 2: Write down the remainder and divide the quotient again.
Step 3: Repeat the step 2 until the quotient is 0.

3. Write the rules to multiply two Binary numbers.
The rule for performing multiplication using binary numbers is the same that of the numbers. 0 × 0 = 0, 0 × 1 = 0, 1 × 0 = 0 & 1 × 1 = 1.

4. Briefly explain the Octal number system.