Stretch: Scaling Ratios Up and Down
I can reason with equivalent ratios and use part-part-whole thinking to solve problems.
🧠 The Challenge
Equivalent ratios are made by multiplying (or dividing) both parts by the same number.
With part-part-whole, the two parts add to the whole.
Example: Paint mixes red : blue = 2 : 3. To make 15 total parts, scale by 3 (since 2 + 3 = 5, and 5 × 3 = 15): that's 6 red and 9 blue.
✏️ Your Turn
0 of 3 checks complete
1. The ratio 2 : 3 is equivalent to…
2. Red : blue = 1 : 4. If there are 5 red, how many blue?
3. Cats : dogs = 3 : 2, and there are 15 animals total. How many cats?
💬 Explain Your Thinking
Explain how you scaled a ratio to solve a problem:
"I started with the ratio blank : blank and multiplied both parts by blank, giving blank : blank."