And since the DIA and SPY own shares in mostly U.S. dividend paying companies, their dividends are mostly qualified. But some of the dividends in the SPY are not. You can look this up yourself using the tax data from the ETF provider.
Fractions are related to division because the top of the fraction is the numerator or the dividend of the fraction and the bottom of the fraction is the denominator or the divisor of the fraction. Minor edit?
This illustrates the following principle: In addition and subtraction, the units must be the same; whatever we add or subtract, we must be able to call them by the same name. We will see this in Lesson 25. The denominator of a fraction has no other function but to name the unit.