Proportional reasoning
Proportional reasoning is a theme within ratio and proportional reasoning [2]. Links to relevant activities and resources are on the right hand side of this page. |
Proportional reasoning involves comparing ratios within or between objects, and understanding that scaling one object while maintaining the ratios involves four variables.When a/b = c/d an increase in a can be compensated by decreasing d, or increasing b, or increasing c. Deciding which quantities to increase or decrease, and whether to achieve this by multiplying or dividing, requires a strong grasp of non-integer arithmetic and the meaning of multiplying as scaling.