The fraction $$\dfrac{214}{263}$$ keeps the same value when both its numerator and denominator are~\uline{~~~~~~~~~~}~. 
Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Basic Understanding of Fractions
The problem is about the basic property of fractions, namely, multiplying or dividing the numerator and denominator by the same number (except $$0$$), the value of the fraction is unchanged. 