### Theory:

Lokesh went to market and bought $$1.2$$ kilogram of vegetables and the next day he again bought $$1.1$$ kilogram of vegetables.

Can you find out how much vegetables did Lokesh bought in both days? To find how many kilograms of vegetables he had bought, we have to add the quantity of vegetables.

To find the difference of two days we have to subtract the vegetables he had purchased on both days.

In previous chapters you have gone through fundamental decimal addition and subtraction. Let us recall it again then we move on to various methods to do the decimal arithmetic operation.

General rules to add decimal numbers:
Step 1: Line up the decimal numbers one by one.

Step 2: Equalize the number of decimal places by adding zeros at the rightmost side of the decimal number.

Step 3: Start adding from the rightmost digit of the decimal number as the usual addition.

Step 4: Add both decimal part and whole number part.

Step 5: Finally, put a decimal point in the answer in the same place as the numbers above it.
Example:
Add $$456.23$$ and $$56.026$$.

Here, to equalize the decimal places, add zero at the end of $$456.23$$.

$\begin{array}{l}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}456.230\\ \underset{¯}{+\phantom{\rule{0.147em}{0ex}}56.026}\\ \phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}512.256\end{array}$

Therefore, the addition of $$456.23$$ and $$56.026$$ is $$512.256$$.