#### Answer

Since, the base of Hindu-Arabic numeral is 10 then the positional values of this system are \[....,{{10}^{4}},{{10}^{3}},{{10}^{2}},10,1\]. So, when a Hindu-Arabic number is written in expanded form, the digits of numeral should be written as product of their positional values in summation format, as shown below:
Consider 1234 is a Hindu-Arabic numeral then the expanded from of this numeral is,
\[1234=\left( 1\times {{10}^{3}} \right)+\left( 2\times {{10}^{2}} \right)+\left( 3\times 10 \right)+\left( 4\times 1 \right)\]