A close look at the results reveals that the Level 4 was shown most frequently with regard to M1 type, while the Level 3 was with regard to M2 type. This result means that recognizing the ‘times’ relationship and finding a missing value may be easier for 3rd students than figuring out the multiple inclusion relationship of part-whole. It is noticeable that the students in Level 4 as for M1 type used various kinds of representations such as pictures, graphs, and expressions (see Figure 1). On one hand, given that these representations were rarely found at lower levels, these representations might help students develop solid multiplicative thinking. On the other hand, as for M2 type, higher level students tended to use more abstract representation such as equation (see Figure 2).