💲 3D | Unit Rates Study Guide

Unit 3: Ratios & Proportions • Lesson 3.4 • Standard: 6.AT.2, 6.AT.2

📘 Key Vocabulary

Rate — a ratio that compares two quantities with different units (example: miles and hours, dollars and pounds). (tasa)
Unit Rate — a rate where the second quantity is 1. It answers the question "how much for one?" (tasa unitaria)
"Per" — means "for each one." Example: $3 per pound means $3 for 1 pound. (por)
Speed — a special kind of rate that compares distance to time. (velocidad)
Better Deal / Best Buy — the option with the lowest unit price (cost per one item). (mejor precio)

🖼️ Visual Example — What is a Unit Rate?

Situation: You buy 4 pounds of apples for $12.

Rate: $12 for 4 pounds → $124 pounds

Unit Rate: $12 ÷ 4 = $3 per pound$31 pound

The unit rate tells you the cost for just ONE pound.

Speed example: A car drives 150 miles in 3 hours.

Unit Rate: 150 ÷ 3 = 50 miles per hour (mph)

🔢 Step-by-Step — Finding a Unit Rate

  1. 1 Write the rate as a fraction: total amountnumber of units
  2. 2 Divide the top number by the bottom number.
  3. 3 Write the answer with "per" and the unit: "___ per 1 ___"
Example: 240 words in 4 minutes

Step 1: 240 words4 minutes
Step 2: 240 ÷ 4 = 60
Step 3: 60 words per minute

Comparing Unit Rates to Find the Better Deal

  1. 1 Find the unit rate for each option.
  2. 2 Compare the unit rates.
  3. 3 The lower unit price = the better deal.
Which is the better deal?

Store A: 6 bottles for $9 → $9 ÷ 6 = $1.50 per bottle
Store B: 8 bottles for $10 → $10 ÷ 8 = $1.25 per bottle

$1.25 < $1.50 → Store B is the better deal!

📐 Formula Box

Unit Rate = Total Amount ÷ Number of Units
Unit Price = Total Cost ÷ Number of Items
Speed = Distance ÷ Time

⚠️ Watch Out!

✏️ Practice Problems

Type just the number (no dollar signs or units needed).

1. A store sells 4 pounds of bananas for $12. What is the unit price per pound?

2. A car travels 280 miles in 4 hours. What is the speed in miles per hour?

3. Store A sells 5 notebooks for $15. Store B sells 8 notebooks for $20. Which store has the better deal? Type "A" or "B".

4. Maria reads 135 pages in 3 hours. What is her reading rate in pages per hour?