A decimal number is a number that comprises of a whole number part and a fractional part. Say for example, 23.75, the number 23 is the whole number part here and the 75 is the decimal portion. But the whole number part and the fractional part is separated by a . or a decimal point. And the digits that follow the dot or the decimal point is a value less than one.
In other words, you can say that the decimals are another way to represent fraction and mixed numbers. Generally, we can write any amount of numbers after a decimal point, but 2 numbers after the decimal point is mostly followed. So instead of 32.65232712, we write it simply as 32.65.
Take for example, the number 45.6 which is none other than 4x10s, 5xOnes and 6 Tenths
45.6= 4×10 + 5×1+6/10
And when we write a decimal number, its place value is extremely important. Say, for example, when you write 438, it means:
8 is in the ones’ position,
3 is in the tens’ position and
4 is in the hundreds’ position
Let’s make things more interesting. For example, let’s write the number 326.235:
When we move to the left of the decimal point each number increases are 10 times bigger. So, for the number 326.235, the numbers to the left of the decimal point are 326.
6 is 6x1s, 2 is 2 x 10s and 3 is 3×100, in other words, Tens is 10 times bigger than Ones and 100s is 10 times bigger than 10s.
Similarly, when you move to the right of the decimal point, each position after the decimal point is ten times smaller.
For the number 326.235, the decimal part of the number is 235, where:
2 = 2/10
3 = 3/100
5 = 5/1000
The decimal point is an important position in a decimal number as any number that is represented to the left of the decimal point is larger than 1 and numbers represented to the right of the decimal point is lesser than 1.
Example 1: What is 5.7?
On the left side of the decimal point is 5, which is the whole number part of the decimal number.
The 7 is the decimal part of the number and it is in the tenth’s position or 7/10
Hence you can say 5.7 is nothing but 5 and 7 tenths.
Example 2: What is 45.23?
On the left side of the decimal point is 45, which is the whole number part of the decimal number.
The 23 is the decimal part of the number and 2 is in the tenth’s position or 2/10 and 3 is in the hundredth’s position or 3/100
Hence you can say 45.23 is nothing but 45 and 2 tenths and 3 hundredths.