Nonproportional reasoning: At a very young age children are in this stage of applying addition reasoning instead of multiplicative. Usually, their reasoning is wrong, since they focus on the number and not on the proportion.
The other stage is Informal reasoning about proportional situations: By this stage, students are able to use multiplicative reasoning with pictures and manipulatives to show proportions, but they are no able to make calculations.
Quantitative reasoning: students will start to use multiplication and division, but still use drawings and manipulatives.
The last stage is Formal proportional reasoning: students are capable to understand and solve proportions.