Respuesta :

10^3 × 10^-3 = 10^0 = 1
irspow
Rule for when multiplying similar bases with exponents is:

(b^c)*(b^d)=b^(c+d)
  
In this case:

(10^3)*(10^-3)

10^(3-3)

10^0

1   (anything raised to the zero power is equal to one)