One milestone in the development of proportional reasoning is a student’s ability to think multiplicatively rather than additively. TEKS 6.4C requires students to give examples of ratios as multiplicative comparisons of two quantities describing the same attribute.
For instance, look at the model below.
For instance, look at the model below.
The following ratios can be made from the model:
3:4 (yellow to red)
4:3 (red to yellow)
3:7 (yellow to total)
7:3 (total to yellow)
In addition, students must recognize that these ratios also represent multiplicative comparisons. Some
examples include:
3:4 (yellow to red)
4:3 (red to yellow)
3:7 (yellow to total)
7:3 (total to yellow)
In addition, students must recognize that these ratios also represent multiplicative comparisons. Some
examples include:
The following blog post describes an activity that can be used to help students understand ratios as
multiplicative comparisons.
multiplicative comparisons.