2. Znayka told Neznayka that to convert kilolunes to kilograms, one needs to divide the mass in kilolunes by 4 and then decrease the obtained number by $4 \%$. Neznayka decided that to convert from kilograms to kilolunes, one should multiply the mass in kilograms by 4 and then increase the obtained number by $4 \%$. By what percentage of the correct value of the mass in kilolunes will he be wrong if he translates this way?

OTBET: by $0.16 \%$.
Solution: One kilolun constitutes $0.25 * 0.96=0.24$ kg. Therefore, in one kilogram there are $25 / 6$ kiloluns. If Nезнайка translates 1 kg, he will get $4 * 1.04=4.16$, which is $99.84\%$ of $25 / 6$.