Solve Decimal Addition: 12.0 + 29.31 Step-by-Step

Decimal Addition with Mixed Place Values

Solve the following exercise:

12.0+29.31

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Solve
00:03 Place 0 in the appropriate position
00:07 Add accordingly, and place
00:13 Place the units, and remember 1 above
00:19 Add 1 to this sum, and place
00:26 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Solve the following exercise:

12.0+29.31

2

Step-by-step solution

To avoid confusion in solving the exercise, we will first add the digit 0 to the number 12.0 as follows:

12.00+29.31 12.00\\+29.31\\

Now let's solve the exercise in order:

Let's add the hundreds after the decimal point:

0+1=1 0+1=1

Let's add the tenths after the decimal point:

0+3=3 0+3=3

Finally, let's add the whole numbers before the decimal point:

2+9=11 2+9=11

We'll add ten to the ones digit before the decimal point and get:

1+1+2=4 1+1+2=4

And we obtain the following:

12.00+29.3141.31 12.00\\+29.31\\41.31

3

Final Answer

41.31

Key Points to Remember

Essential concepts to master this topic
  • Alignment: Line up decimal points vertically before adding
  • Technique: Add zeros as placeholders: 12.0 becomes 12.00 to match 29.31
  • Check: Verify by counting decimal places: 12.00 + 29.31 = 41.31 ✓

Common Mistakes

Avoid these frequent errors
  • Adding without aligning decimal points
    Don't just add digits from right to left like 120 + 2931 = wrong answer! This ignores place values and gives incorrect results. Always align decimal points vertically and add zeros as placeholders to match decimal places.

Practice Quiz

Test your knowledge with interactive questions

Choose the correct writing form:

FAQ

Everything you need to know about this question

Why do I need to add a zero to make 12.0 into 12.00?

+

Adding the zero creates matching decimal places! When 12.0 becomes 12.00, you can easily line up with 29.31 and add column by column without confusion.

What if the numbers have different amounts of decimal places?

+

No problem! Just add zeros as placeholders to make them match. For example, 5.2 + 3.456 becomes 5.200 + 3.456 for easier addition.

Do I always need to write out all the zeros?

+

While not always required, it's highly recommended for beginners! Writing zeros prevents mistakes and makes the addition process much clearer and more organized.

How do I know where to put the decimal point in my answer?

+

Easy! The decimal point in your answer goes in the same column as the decimal points in the numbers you're adding. Keep everything lined up vertically.

What if I get confused about which column to add first?

+

Start from the rightmost column (furthest right) and work your way left, just like with whole numbers. This follows the same pattern you already know!

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Decimal Fractions - Advanced questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations