A bag holds 6 tiles: 2 lettered and 4 numbered. Without looking, you choose a tile. What is the probability of drawing a number?

You take the total number as the denominator and the amount of each become your numerators. For numbered it's 4/6 then you divide both the top and bottom number by two and you get 2/3 or 66%.

4/6 because the bag holds six tiles total so 4 of the 6 are numbered so you would have 4/6 of a chance of picking a numbered tile.