Page 32 - Viva ICSE Computer Studies 7 : E-book

Step 2: Increase the power one by one, keeping the base fi xed at 8.
Step 3: Add all the products to get the decimal number.

Let’s understand with the help of an example.

Example: (345) = (?)
8 10

(3 4 5) 8 Think and Discuss

5 × 8 0 = 5 Which number system has 8 as

4 × 8 1 = 32 its base?

3 × 8 2 = 192
229

(345) = (229)
8 10
Hexadecimal Number System

The hexadecimal number system consists of 16 digits, i.e., 0 to 9 digits and the letters A to
F, where 10 represents A, 11 represents B, 12 represents C, 13 represents D, 14 represents E
and 15 represent F. Hence, the base of hexadecimal number system is 16. Some examples of
hexadecimal number system are 54A, 64A and 4D2.

Conversion of Hexadecimal Number System into Decimal Number System

Following are the steps that need to be followed to convert hexadecimal number system into
decimal number system.
Step 1: Multiply each digit with its positional value, which is in terms of powers of 16, starting
from the extreme right digit.

Step 2: Increase the power one by one, keeping the base fi xed at 16.

Step 3: Add all the products to get the decimal number.

Example: Let’s understand with the help of an example.
(4D2) = (?)
16 10
(4 D 2)
16
0
2 × 16 = 2
1
D × 16 = (D = 13) = 208
2
4 × 16 = 1024
1234

(4D2) = (1234)
16 10

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