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<h2>Decimal numbers are a base 10 numeral system.</h2>

<p>In Roman calculation, stones are placed on lines representing units, tens, hundreds and thousands. The spaces between the lines are used to represent intermediate values that is 5, 50, 500. </p>
<p><b>Carrying</b>: So it is never necessary to use more than 5 stones on a line or more than 2 stones in a space. This is because 5 stones on a line can be replaced by one stone in the space above and 2 stones in a sp