A red herring is normally a dried fish turned red by smoke, but in the case of an investigation, a red herring refers to a clue intended to be misleading or distracting. In this sense, there may be extra information in a problem.
In real life, we do well to develop skills that help us discern between the important information and the unimportant information. At the same time, we need to determine when there is information missing, in which case we must be willing to say the problem cannot be solved. Perhaps if we can figure out what information is needed, we will be able to find it. Figuring out where the gaps are is when we employ our investigation tool of INI, Identifying Necessary Information.
This is obvious in Math where there is often extra information - a distractor or an extra number in the problem. We like to leave that information alone, since it can really mess up our solution. We can think of this as EUNI, Eliminating UnNecessary Information.
Let the teacher lead you through some of these problems.
And yes! Before you ask, yes, the same thing happens with Reading. Put on your best INI and EUNI hats, and try out some stories with holes. For this activity, you may only ask yes and no questions to solve the problems.
During your personal or assigned reading, the same is true. Great readers stop to ask themselves questions during reading in order to make inferences and predictions, and in order to draw conclusions. It's one of the ways we use clues to better understand what we read.