Guide to solving multi-step customary weight word problems (Grade 3)

📚 Understanding Customary Weight

Customary weight refers to the system of measurement commonly used in the United States. It includes units like ounces, pounds, and tons. Solving multi-step word problems involving these units requires a good understanding of the relationships between them and careful attention to detail.

📜 A Brief History

The customary weight system has roots in various historical measuring systems, including the English system. Over time, it has been standardized, but its origins are diverse and reflect a long history of trade and measurement.

⚖️ Key Principles

• 🔗 Conversion Factors: Remember the relationships between the units:
• ⚖️ 1 pound (lb) = 16 ounces (oz)
• 🧱 1 ton (T) = 2000 pounds (lb)
• ➕ Addition and Subtraction: When adding or subtracting, make sure the units are the same. If not, convert them first.
• ➗ Multi-Step Problems: Break down the problem into smaller, manageable steps. Identify what information you have and what you need to find.

📝 Example Problems

Example 1:

Sarah has 5 pounds and 4 ounces of flour. She uses 2 pounds and 8 ounces to bake a cake. How much flour does she have left?

Step 1: Convert everything to ounces.

• ⚖️ 5 pounds = $5 \times 16 = 80$ ounces
• ➕ Total ounces initially: $80 + 4 = 84$ ounces
• 🍰 2 pounds = $2 \times 16 = 32$ ounces
• ➖ Total ounces used: $32 + 8 = 40$ ounces

Step 2: Subtract the used amount from the initial amount.

• ➖ Remaining ounces: $84 - 40 = 44$ ounces

Step 3: Convert back to pounds and ounces.

• ➗ Pounds: $44 \div 16 = 2$ with a remainder of $12$
• ✅ Answer: Sarah has 2 pounds and 12 ounces of flour left.

Example 2:

A truck is carrying 2 tons of gravel. It delivers 1500 pounds to a construction site. How much gravel is left on the truck in pounds?

Step 1: Convert tons to pounds.

• 🚚 2 tons = $2 \times 2000 = 4000$ pounds

Step 2: Subtract the delivered amount from the initial amount.

• ➖ Remaining pounds: $4000 - 1500 = 2500$ pounds
• ✅ Answer: There are 2500 pounds of gravel left on the truck.

✍️ Practice Quiz

Solve the following problems, showing your work:

1. 🎁 John has 3 pounds and 7 ounces of candy. He gives away 1 pound and 10 ounces. How much candy does he have left?
2. 🍎 A box contains 8 pounds of apples. Each apple weighs 4 ounces. How many apples are in the box?
3. 🚚 A truck can carry 3 tons of cargo. It is already carrying 4500 pounds. How many more pounds can it carry?

💡 Tips for Success

• 🎯 Read Carefully: Understand what the problem is asking before you start solving.
• ✏️ Show Your Work: This helps you keep track of your steps and makes it easier to find mistakes.
• 🔎 Check Your Answer: Does your answer make sense in the context of the problem?

✅ Conclusion

Mastering multi-step customary weight word problems involves understanding the relationships between different units of weight and applying basic arithmetic operations. With practice and careful attention to detail, you can confidently solve these types of problems.