Theory:

Meena went to a store to buy toothpaste. The cost of toothpaste is \(20\) \(rupees\) and \(50\) \(paise\). She doesn't know what cost is this.
  
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Do you know the cost of the toothpaste?
 
We will help her to find the cost of the toothpaste.
 
Let us first convert \(paise\) to \(rupees\).
 
\(100\) \(paise\) \(=\) \(₹1\).
 
\(1\) \(paise\) \(=\) \(₹\)1100.
 
\(50\) \(paise\) \(=\) 50100 \(=\) \(₹0.50\).
 
Now, add \(₹20\) with \(₹0.50\).
 
\(20\) \(rupees\) \(+\) \(50\) \(paise\).
 
20.00+0.50¯20.50
 
So, the cost of toothpaste is \(₹20.50\).
To convert paise to rupees, divide the paise by \(100\).
 
To convert rupees to paise, multiply the rupees by \(100\).
Example:
1. Convert \(75\) \(paise\) to \(rupees\).
 
\(1\) \(paise\) \(=\) \(₹\)1100.
 
\(75\) \(paise\) \(=\) \(₹\)1100×75 \(=\) \(₹0.75\)
 
Therefore, \(75\) \(paise\) \(=\) \(₹0.75\).
 
 
2. Convert \(₹5\) \(rupees\) to \(paise\).
 
\(₹1\) \(=\) \(100\) \(paise\)
 
\(₹5\) \(=\) 5×100 \(=\) \(500\) \(paise\)
 
Therefore, \(₹5\) \(=\) \(500\) \(paise\).
Multiply a decimal number by \(10\):
 
Move the decimal point in the product by one place to the right.
 
Multiply a decimal number by \(100\):
 
Move the decimal point in the product by two places to the right.
 
Multiply a decimal number by \(1000\):
 
Move the decimal point in the product by three places to the right.
Example:
1. Convert \(₹4.76\) \(rupees\) to \(paise\).
 
\(₹1\) \(=\) \(100\) \(paise\).
 
\(₹4.76\) \(=\) \(4.76 \times 100\) \(=\) \(476.00\) \(paise\).
 
Therefore, \(₹4.76\) \(=\) \(476\) \(paise\).
 
 
2. Convert \(₹10.80\) \(rupees\) to \(paise\).
 
\(₹1\) \(=\) \(100\) \(paise\).
 
\(₹10.80\) \(=\) \(10.80 \times 100\) \(=\) \(1080.00\) \(paise\).
 
Therefore, \(₹10.80\) \(=\) \(1080\) \(paise\).
Important!
\(₹1\) \(=\) \(100\) \(paise\).
 
\(1\) \(paise\) \(=\) \(₹\)1100 \(=\) \(₹0.01\).