First change the 230 grams to kilograms or 1 kilogram to grams.
The units have to be the same.
Next set up a proportion.
Cross multiply to solve the proportion.
1 kg = 1000g
230 g/30 biscuits = 1000g/x biscuits
230x = 30(1000)
230x = 30000
divide both sides by 230
x =130 biscuits