Writing a number with a decimal is known as decimal notation. It is a way of showing parts of a whole when the whole is a power of ten. In other words, decimals are another way of writing fractions whose denominators are powers of ten. Just as the counting numbers are based on powers of ten, decimals are as well.

They are written as an extension of the place value we use to identify the whole numbers. Actually, the portion on the right of the decimal point is the portion of the number/fraction in the power of ten.

For example

\(6.004 = 6 + \frac{4}{1000}\)

Perhaps, there are no other numbers that entice people in careless calculation errors. Therefore, one of the best things a student could do is ALMOST always convert decimals to fractions or other form of numbers that are easier to deal with.





Place and Face Value

Place Value	Face Value
Place value is the value represented by a digit in a number according to its position in the number.	Face value is the actual value of a digit in a number.
To get the place value of a number, we multiply the digit value with its numerical value. For example, in the number 452, the place value of 5 is (5 × 10) = 50, since 5 is in tens place.	The face value of a digit is the number itself. For example, in the number 452, the face value of 4 is 4.
The place value of a number depends upon the position of the digit in the number.	The face value is independent of the position of the digit in the number.
The place value of a digit in ones place is always a single digit and the place value of every next digit to the left increases by one more digit.	The face value of a number is always a single digit.

Convert Decimals to Fractions or Mixed Numbers

Suppose we have \(5.03\) as decima.

5 is the ones
0 is the tenths
3 is the hundredths

\(5.03=5 \frac{3}{100}\)


Round a decimal

Step 1. Locate the given place value and mark it with an arrow.

Step 2. Underline the digit to the right of the given place value.

Step 3. Is this digit greater than or equal to 5?
Yes - add 1 to the digit in the given place value.
No - do not change the digit in the given place value.

Step 4. Rewrite the number, removing all digits to the right of the given place value.


For example 25.3679.

We have the 7 after the six, so the number will become 25.37

Going further, we will have the 7 after the three so the number will 25.4

After the decimal point, our number is 4, which is < to 5 so the number will become 25

Helpful could be the Rounding Numbers Calculator