The French pour cent means per hundred, so $1$ percent is $1$ per 100.
That becomes $\frac{1}{100}$ part of the total. In writing: 1% = $\frac{1}{100}=0.01$.
And 12% of $500$ is the $\frac{12}{100}$ part of 500. That is $0.12\times 500=60$.

• What percentage is $24$ of 60?
  Answer: $\frac{24}{60}\approx 0.369=36.9$%.

• The number $24$ increases to $27$, by how many percent is that?
  Answer: $\frac{27-24}{24}=0.125=12.5$%.

• The number $24$ increases with $6$%, how much will it become?
  Answer: $24\times 1.06=25.44$.

• The number $24$ decreases with $6$%, how much will it become?
  Answer: $24\times 0.94=22.56$.

• The number $24$ is $6$% of the total, how much is the total?
  Answer: $0.06\times \text{total}=24$, so the total is $\frac{24}{0.06}=400$.

• A number increases with $6$% to $60$, what is the number?
  Answer: $\text{number}\times 1.06=60$, so the number is $\frac{60}{1.06}\approx 56.60$.