With regard to the levels of multiplicative thinking, Clark and Kamii (1996) interviewed 336 children in grades 1-5 using a multiplication task. As a result, four developmental levels were identified in children’s progression from additive to multiplicative thinking. For example, the children in Level 1 thought only qualitatively without referring to any numerical reference. The children in Level 2 showed additive thinking with a numerical sequence, whereas their counterparts in Level 4 reasoned multiplicatively and used the term “times” properly. The children in Level 3 demonstrated a mixture of additive and multiplicative thinking, so-called transitional thinking. Siemon and his colleagues (2006) proposed a learning assessment framework for multiplicative thinking. They developed the framework for multiplicative thinking comprised of 8 relatively discrete levels, in which students from Level 1 to 4 usually rely on additive reasoning while their counterparts from Level 5 to 8 can think multiplicatively using a broader range of numbers.