What percent of 3.8 is 38?

With percent questions the best way to do it is to use the formula %/100 = is/of.  I teach my students this and it works every time.

Your question "What percent of 3.8 is 38?" will fit right into the formula.  % is the unknown, so it goes in the formula as x.  Of is the number 3.8, and is will be 38.  Fill these into the formula, cross multiply and solve for x.

x/100 = 38/3.8 (cross multipy)

3.8x = 3800 (divide both sides by 3.8 to get x alone)

3.8x/3.8 = 3800/3.8

x = 1000%

This makes sence because 3.8 is much smaller than 38, so it makes sence that 38 is 1000% higher than 3.8.  Hope this helps.  :)