How to solve decimal addition word problems (Grade 5 steps)

📚 Understanding Decimal Addition Word Problems

Decimal addition word problems involve adding numbers that contain a decimal point. These problems often appear in real-life scenarios, such as calculating expenses, measuring ingredients, or determining distances. The key to solving these problems is to carefully read the problem, identify the numbers to be added, and set up the addition correctly.

🧮 Key Principles of Decimal Addition

• 📏 Aligning Decimal Points: This is the most crucial step. Make sure all decimal points are lined up vertically. This ensures that you are adding tenths to tenths, hundredths to hundredths, and so on.
• ➕ Adding Placeholders (Zeros): If the numbers have different numbers of decimal places, add zeros to the end of the shorter number(s) so that all numbers have the same number of decimal places. This helps prevent mistakes.
• ➕ Adding Columns: Start adding from the rightmost column (smallest place value) and move to the left. Carry over if the sum in any column is greater than 9.
• 📍 Placing the Decimal Point: In the final answer, the decimal point should be directly below the decimal points in the numbers you added.

📝 Step-by-Step Guide to Solving Decimal Addition Word Problems

1. 📖 Read and Understand: Read the word problem carefully. Identify what the problem is asking you to find.
2. 🔢 Identify the Numbers: Determine the numbers in the problem that need to be added together. Pay attention to the units (e.g., dollars, meters, kilograms).
3. ✍️ Set Up the Addition: Write the numbers vertically, making sure to align the decimal points. Add placeholders (zeros) if necessary.
4. ➕ Add the Numbers: Add the numbers column by column, starting from the right. Carry over when necessary.
5. 📍 Place the Decimal Point: Place the decimal point in the answer directly below the decimal points in the numbers you added.
6. ✅ Check Your Work: Review your addition to make sure you didn't make any mistakes. Does the answer make sense in the context of the problem?
7. ✍️ Write the Answer: Write the final answer with the correct units.

➕ Real-World Examples

Example 1: Shopping Trip

Sarah bought a book for $7.50, a pen for $2.25, and a notebook for $3.75. How much did she spend in total?

1. Set Up: Align the decimal points and add placeholders:
   $$\begin{array}{@{}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c} & 7 & . & 50 \\ & 2 & . & 25 \\ + & 3 & . & 75 \\ \hline & & & \\ \end{array}$$
2. Add: Add the numbers column by column:
   $$\begin{array}{@{}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c} & 7 & . & 50 \\ & 2 & . & 25 \\ + & 3 & . & 75 \\ \hline & 13 & . & 50 \\ \end{array}$$
3. Answer: Sarah spent $13.50 in total.

Example 2: Measuring Distance

John walked 1.25 kilometers on Monday, 2.5 kilometers on Tuesday, and 1.75 kilometers on Wednesday. How far did he walk in total?

1. Set Up: Align the decimal points:
   $$\begin{array}{@{}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c} & 1 & . & 25 \\ & 2 & . & 50 \\ + & 1 & . & 75 \\ \hline & & & \\ \end{array}$$
2. Add: Add the numbers column by column:
   $$\begin{array}{@{}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c@{\thinspace\thinspace}c} & 1 & . & 25 \\ & 2 & . & 50 \\ + & 1 & . & 75 \\ \hline & 5 & . & 50 \\ \end{array}$$
3. Answer: John walked a total of 5.5 kilometers.

✍️ Practice Quiz

1. Maria bought a sandwich for $6.75 and a drink for $2.50. What was the total cost?
2. A piece of wood is 3.45 meters long, and another piece is 2.8 meters long. If you put them end-to-end, what is the total length?
3. Tom ran 4.6 kilometers on Saturday and 3.75 kilometers on Sunday. How far did he run in total?
4. Lisa spent $15.50 on groceries and $7.25 on snacks. How much did she spend in all?
5. A plant grew 2.35 inches in one week and 1.8 inches the next week. What was the total growth?

💡 Tips for Success

• ✅ Double-Check: Always double-check your work, especially the alignment of decimal points.
• 📝 Practice Regularly: The more you practice, the better you'll become at solving these problems.
• 🤝 Ask for Help: If you're struggling, don't hesitate to ask a teacher, tutor, or friend for help.

⭐ Conclusion

Solving decimal addition word problems becomes straightforward with a clear understanding of the steps and principles involved. Remember to read carefully, align decimal points, and practice regularly. With these tips, you'll be well-equipped to tackle any decimal addition problem that comes your way!