Divide:
$$ 403.8 \div 30 $$
The above question can be written as,
$$ 403.8 \div 30 =\dfrac{403.8}{30} $$
Multiplying both numerator and denominator by 10, we get,
$$ = \dfrac{403.8 \times 10}{30 \times 10}=\dfrac{4038}{300}$$
By long division (as shown in image), We get
$$ 403.8\div30=\dfrac{4038 }{300} = 13.46 $$