Adding and subtracting SI prefixes creates multiples and submultiples; however, as the unit is exponentiated, the quantitiesgrow exponentially by the corresponding power of 10. For example, 1 kilometre is 103 (one thousand) times the length of 1 metre, but 1 square kilometre is (103)2 (106, one million) times the area of 1 square metre, and 1 cubic kilometre is (103)3 (109, one billion) cubic metres.
SI prefixes applied
Square Meter Unit Conversion Visual Aid
The square metre may be used with all SI prefixes used with the metre.
Unicode has several characters used to represent metric area units, but these are for compatibility with East Asian character encodings and are not meant to be used in new documents.[2]
U+33A1㎡SQUARE M SQUARED
U+33A2㎢SQUARE KM SQUARED
U+3378㍸SQUARE DM SQUARED
U+33A0㎠SQUARE CM SQUARED
U+339F㎟SQUARE MM SQUARED
Instead, the Unicode superscriptU+00B2²SUPERSCRIPT TWO can be used, as in m².