106/500 as a decimal is: 0.212.
You can easily find the decimal of a fraction by doing long division or inserting the fraction in a calculator (which teachers usually allow their students to use a calculator even on tests... unless if the test is about long division, etc).
Long division is pretty hard to do without a pen and paper, but the steps to do long division are: divide the number on the right by the left number - multiply the number on the left by the top number - subtract the number on the right by the number below it - bring down, and then repeat if you can.