<P> The square of mn, mn being a two - digit integer, can be calculated as </P> <Dl> <Dd> 10 × m (mn + n) + n </Dd> </Dl> <Dd> 10 × m (mn + n) + n </Dd> <P> Meaning the square of mn can be found by adding n to mn, multiplied by m, adding 0 to the end and finally adding the square of n . </P>

14 less than the product of 3 and a number