If the value of Avogadro number is 6.023 × 10 ^ 23 mo l ^ – 1 and...

$\text{K} = \dfrac{\text{R}}{{\text{N}}_{\text{A}}}$

$∴ R = {\text{k.N}}_{\text{A}}$

$= \text{6.023} \times {\text{10}}^{\text{23}} \times \text{1.380} \times {\text{10}}^{- 2 3} {J. mol}^{-1} {\text{k}}^{-1}$

There are 4 significant figures in each term.

Hence, these be 4 significant figure in R.