**Important Concepts and Formulas**

2. A decimal number has two parts: a
whole number part (integral part) and a decimal part.

3. The number of digits in the decimal
part of a decimal number determines the decimal places of that number.

4. Decimals having the same number of
decimal places are called like decimals, otherwise they are unlike decimals.

5. Unlike decimals can be converted into
like decimals by adding required number of zeros at the end of the decimal
part.

6. To compare two decimal numbers, first
we compare the whole number part. If they are equal then the tenth part is
compared. If they are also equal, then the subsequent parts are compared.

7. Every decimal number can be converted
as a fraction and vice versa.

8. To add or subtract decimals, convert
them into like decimals. Then add or subtract them like whole numbers by
keeping decimal points of the given decimals in the same column.