Subtracting Decimals
Decimals are more than just a math concept—they’re a vital part of daily life, from grocery shopping to taking measurements. While subtracting decimals might seem challenging at first, it’s actually quite similar to regular subtraction — just with extra attention to aligning the decimal points. In this blog post, we’ll break down the process step by step, provide helpful tips, and even tackle tricky scenarios like regrouping and double borrowing.
How Do You Subtract Decimals?
Step 1: Align the Decimal Points
The first step in subtracting decimals is aligning the numbers by their decimal points. This ensures each digit lines up correctly in its place value (ones, tenths, hundredths, etc.).
For example: Subtract 8.32 − 4.76:
8.32
- 4.76
*Helpful Tip: If one number has fewer decimal places, we add zeros to the end to balance it out.
For example: Subtract 5 − 3.14:
5.00
- 3.14
Step 2: Start Subtracting from the Right
In this next step, begin subtracting from the rightmost column, just as you would in whole-number subtraction. If the top digit is smaller than the bottom digit, you’ll need to regroup (borrow).
For example: Subtract 7.5 − 3.28:
7.50 → Add a zero to balance
- 3.28
To solve this equation:
Start with the hundredths place → 0 − 8 isn’t possible, so we borrow from the tenths column.
Reduce 5 (tenths) to 4 and turn 0 (hundredths) into 10.
Now subtract 10 − 8 = 2.
Move to the tenths place: 4 − 2 = 2
Finish with the ones place: 7 − 3 = 4.
Final answer:
7.50
- 3.28
4.22
Step 3: Borrowing for Tricky Situations
Sometimes, borrowing involves more than one column—this is called double borrowing. Let’s look at an example.
Subtract 10.03 − 7.89:
10.03
- 7.89
To solve this equation:
Start with the hundredths place → 3 − 9 isn’t possible. In this case, we borrow from the tenths column, but 0 (tenths) has nothing to give! So, we’ll need to borrow from the ones column first.
Reduce 10 (ones) to 9, turn 0 (tenths) into 10.
Now we borrow from 10 (tenths) to turn 3 (hundredths) into 13.
Subtract: 13 − 9 = 4 in the hundredths place.
Move to the tenths place: 9 − 8 = 1.
Finally, we subtract the ones place: 9 − 7 = 2.
Final answer:
10.03
- 7.89
2.14
*Helpful Tip: Take your time with borrowing—double-check each place value to ensure accuracy!
Step 4: Tackling Larger Numbers
When subtracting numbers with several decimal places, the same principles apply. Just remember to align the decimal points and add zeros where needed.
For example: Subtract 15.006 − 9.8792:
15.0060 → Add a zero to match decimal places
− 9.8792
To solve this equation:
Start with the ten-thousandths place: 0 − 2 → borrow from the thousandths place.
Work through each column, borrowing as needed.
Don’t forget to bring the decimal point straight down into your answer!
Final answer:
15.0060
- 9.8792
5.1268
Step 5: Double-Check Your Work
After completing the subtraction, reminder to always double-check your work! You can do this by adding the difference to the smaller number—it should equal the original larger number.
For example: Verify 8.32 − 4.76 = 3.56:
4.76
+ 3.56
8.32 ✅
Key Tips to Master Subtracting Decimals:
Align decimal points: Always line up numbers by their decimal points for accurate subtraction.
Add zeros: Balance decimal places by adding zeros where needed.
Borrow carefully: When borrowing, ensure each place value is correctly adjusted.
Practice tricky scenarios: Focus on regrouping and double borrowing for more complex problems.
Double-check your work: Use addition to confirm your result.
With these steps and tips, you're all set to subtract decimals with confidence! Remember, practice makes perfect—try solving a variety of problems to master these techniques! For a deeper dive into subtracting decimals and to see more examples in action, be sure to watch our YouTube video!
Click the link below and start mastering subtracting decimals today!
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