To do this, move the decimal in such a way that there is a non-zero digit to the left of the decimal point. The number of decimal places you shift will be the exponent by 10. If the decimal is shifted to the right the exponent will be negative. If the decimal is shifted to the left, the exponent will be positive. So,
Then as the point moved 10 places to the left you have
[tex]4.21\times10^{10}[/tex]
