In a monotonous relationship, the steps between the different numbers are approximately or exactly the same. Since the steps are always roughly the same size, there will only be addition or subtraction (and not multiplication or division). The simplest example of a monotonous relationship is:

Not many people will have trouble finding the pattern in the above example, the answer is 9. Also a monotonous relationship where the numbers get smaller evenly is relatively easy to spot.

However, variations on a monotonous relationship are possible that are more difficult to recognize. By accurately drawing the addition arches, these types of patterns become clearly recognizable and you can solve them relatively easily. If the addition arches don't show a clear pattern, you will have to look for a different pattern.

We will first work out a number of examples and show you how to draw the arches. Then you can do 3 practice tasks yourself.