It contains the Introduction of decimals, Addition & Subtraction process and so on. It is applicable for any standard's student to understand decimals process. It has been made with the help of sites.

1. DECIMALS
The number of digits contained in the decimal part of a given decimal number gives the number
of decimal places.
Examples:
1. The number 5.76 has 2 decimal places.
2. The number 0.315 has 3 decimal places.
3. The number 86.261 has 3 decimal places.
4. The number 912.67 has 2 decimal places.
To understand about the explanation of a decimal numbers we must first know about the Place
Value.
For example:
Let us take a decimal number 42.37
• The number is read as forty two and thirty seven hundredths or forty two point three
seven.
• In the decimal number the whole number part is 42 and the decimal part is 0.37.
• In the whole number part 42
o Where The place of 2 is ones or unit and its place value is 2 × 1 = 2.
o The place of 4 is tens and its place value is 4 × 10 = 40.
• In the decimal part 0.37
o The place of 3 is tenths and its place value is 3 × 1/10 = 3/10 = 0.3.
o The place of 7 is hundredths and its place value is 7 × 1/100 = 7/100 = 0.07.
We can also write the number in the expanded form as 42.37 = 40 + 2 + 0.3 + 0.07
= 4 10 + 2 1 + 3/10 + 7/100
1. Add the decimals:
● Write down the decimal numbers, one number under the other number and line up the
decimal points.
● Convert the given decimals to like decimals.

2. ● Arrange the addends in such a way that the digits of the same place are in the same
column.
● Add the numbers from right as we carry addition usually.
● Remember to place the decimal point down in the answer in the same place as the
numbers above it.
EXAMPLES:
We have 1.83 + 21.105 + 236.8 + 0.9
Converting all the addends to like decimals
1.830 + 21.105 + 236.800 + 0.900
Arranging the addends in columns and on
adding we get
Answer: 260.635
(ii) 7.39, 65.007, 213.8 and 91.2
Solution:
We have 7.39 + 65.007 + 213.8 + 91.2
Converting all the addends to like decimals
7.390 + 65.007 + 213.800 + 91.200
Arranging the addends in columns and on adding we get
Answer: 377.397

3. Word problems on adding decimals:
2. Terry spent $33 and 65 cents on Monday, $21 on Tuesday and $9 and 7 cents on Wednesday.
Find the total money spent by her in three days altogether.
Solution:
Terry spent on Monday = $43 and 65 cents = $33.65
She spent on Tuesday = $21 = $21.00
She spent on Wednesday = $9 and 5 cents = $9.07
Therefore, total amount spent by Terry = $(33.65 + 21.00 + 9.07) = $63.72
3. First number is 85.99, second number is 107.81 and the third number is 19.207. Find the sum
of the three numbers.
Solution:
First number = 85.99
Second number = 107.81
Third number = 19.207
Therefore, sum of three numbers = (85.99 + 107.81 + 19.207) = 213.007

4. Subtracting Decimals
To subtract decimal follow the below steps:
● Write down the two decimal numbers, one number under the other number and line up the decimal points.
● Convert the given decimals to like decimals.
● Write the smaller decimal number under the larger decimal number in the column.
● Arrange the decimal numbers in the column in such a way that the digits of the same place are
in the same column.
● Subtract the numbers in the column from the right.
● Remember to place the decimal point down in the answer in the same place as the numbers above it.
Worked-out problems to find the difference between the two decimal numbers:
Read the above explanation step-by-step and try to understand the examples on subtraction of decimals.
1. Subtract the decimals:
(i) 27.59 from 31.4
Solution:
We have 27.59 from 31.4
Converting both the decimal numbers into like decimals,
31.40 - 27.59
Now arrange them in columns and subtract we get
Answer: 3.81

5. (ii) 243.86 from 402.1
Solution:
We have 243.86 from 402.1
Converting both the decimal numbers into like
decimals,
402.10 - 243.86
Now arrange them in columns and subtract we get
Word problems on subtraction of decimals:
2. Aaron father gave him $100. He bought a math book for $61.35. How much money is left with
him?
Solution:
Aaron father gave him = $100.00
Aaron spent on purchasing the math book = $61.35
Therefore, amount left with him = $(100.00 - 61.35) = $38.65
3. One number is 107.06 and the other number is 79.17. Find the difference between both the
numbers.
Solution:
One number is 107.06
The other number is 79.17
Therefore, the difference between both the numbers = 107.06 - 79.17 = 27.89