I use this activity to reinforce student understanding for predicting products or making sense of their products.Before this activity students should understand multiplication expressions and/or equations.  Students should know that the first factor represents the number of groups, and the second factor represents the size of the group.  For instance, 5 x 3 means five groups of three, or taking 3, five whole times.  So with fractions, 2/5 x 3/4, is the same as 2/5 of 3/4, taking a fraction of a fraction, or a part of a part.Students should use their understanding of expressions and/or equations to help them make predictions about the product.  For instance, if they are taking a part of a part (fraction times a fraction) it makes sense that their product would be less than.  If multiplying by 2/2 or 1, they are taking the whole amount, and only the whole, so their product would be equal to.  Lastly, if they are multiplying by a number greater than a whole or one, then it makes sense that the product will be greater than.  The whole amount and more is being taken, so again a greater product is reasonable.