In building houses and other structures, we often see workers used framed wire screen to separate stones from sand before it is mixed with cement. They want the sand to be as fine as possible before they mix it with the cement. This will result to a better cement mixture resulting to stronger walls, flooring, and foundation of any building. On the other hand, carpenters love to sip coffee early in the morning before starting to work. They usually brew coffee and use cloth to filter the insoluble ground coffee from the liquid.These two processes of separating mixtures involve filtering and sieving that will be discussed in this lesson.