Teacher Script & Notes
What to say / Spoken Script
A ratio compares parts to parts. Let's look at a ratio of 2:3. This means for every 2 blue units, we have 3 yellow units, giving us 5 total parts. To divide $50 in this ratio, we divide by the 5 total parts to find one part ($10), and then multiply.
What to do / Action Guide
Point to the blue and yellow colored circles representing the ratio of 2:3.
Pedagogical Tips
Encourage students to always find the 'value of one part' first.
What to say / Spoken Script
In direct proportion, as one value doubles, the other doubles ($y = kx$). In inverse proportion, as one value doubles, the other halves ($y = k/x$). Notice how direct proportion is a straight line, while inverse is a curve.
What to do / Action Guide
Highlight the straight line of direct proportion and the hyperbola curve of inverse proportion.
Pedagogical Tips
Direct proportion always passes through the origin (0,0).
Step 1: Introduction
Step 1 of 2
Was this lesson helpful? Rate this Course
Discussion
Loading comments...