Introduction
Subtraction is one of the fundamental operations in mathematics that we use almost every day, often without even thinking about it. From figuring out how much money you have left after a purchase to measuring ingredients for a recipe, subtraction helps us understand what remains when something is taken away.
This post will walk you through a clear, step-by-step process for solving a specific subtraction problem: finding the difference between 11.97 and 7.23. By the end, you’ll understand exactly how to handle decimal subtraction and feel more confident in your math skills.
How to Subtract 7.23 from 11.97
Solving this problem is straightforward once you break it down into smaller steps. The key is to keep the numbers organized and work through each column one at a time, from right to left.
Step 1: Align the Numbers Correctly
First, write the numbers vertically, one on top of the other. The most important rule in decimal subtraction is to align the decimal points. This ensures that you subtract the correct place values from each other (hundredths from hundredths, tenths from tenths, and so on).
Place the larger number (11.97) on top and the smaller number (7.23) below it.
11.97 - 7.23 -------
Step 2: Subtract the Hundredths Place
Start with the rightmost column, which is the hundredths place. Subtract the bottom digit from the top digit.
- 7 – 3 = 4
Write the result (4) below the line in the hundredths column.
11.97
- 7.23
-------
._4
Step 3: Subtract the Tenths Place
Next, move one column to the left to the tenths place. Subtract the bottom digit from the top digit.
- 9 – 2 = 7
Write the result (7) below the line in the tenths column, and remember to place your decimal point.
11.97
- 7.23
-------
_.74
Step 4: Subtract the Ones Place
Finally, move to the left of the decimal point and subtract the whole numbers. Here, we are subtracting 7 from 11.
- 11 – 7 = 4
Write the result (4) below the line in the ones column.
11.97 - 7.23 ------- 4.74
The final answer is 4.74.
Understanding Borrowing in Subtraction
In our example, we didn’t need to “borrow” because each top digit was larger than the bottom digit in its respective column. However, borrowing is a common technique you’ll need for many subtraction problems.
Let’s look at a different example: subtracting 2.48 from 5.32.
- Align the numbers:
5.32 - 2.48 -------
- Subtract the hundredths: You can’t subtract 8 from 2. So, you “borrow” from the next column to the left (the tenths place). The 3 in the tenths place becomes a 2, and the 2 in the hundredths place becomes 12.
-
- 12 – 8 = 4
- Subtract the tenths: Now you have 2 in the tenths place, and you need to subtract 4. Again, the top number is smaller. So, you borrow from the ones place. The 5 becomes a 4, and the 2 in the tenths place becomes 12.
-
- 12 – 4 = 8
- Subtract the ones:
-
- 4 – 2 = 2
The final answer is 2.84. Borrowing is simply a way of regrouping numbers to make subtraction possible in every column.
Real-World Uses for Subtraction
You might not be subtracting 11.97 and 7.23 every day, but the skill itself is essential. Here are a few real-world scenarios where you use subtraction:
- Managing Money: Calculating your change after buying coffee, balancing your bank account, or figuring out how much you have left in your weekly budget.
- Cooking and Baking: Adjusting a recipe by reducing the amount of an ingredient. If a recipe calls for 2 cups of flour and you only want to make half, you subtract 1 cup.
- Time Management: Figuring out how much time you have left to complete a task. If you have a 1-hour meeting and 20 minutes have passed, you have 40 minutes remaining.
- Tracking Fitness Goals: If your goal is to run 5 miles and you’ve already run 2.5, you subtract to find you have 2.5 miles left.
Improve Your Subtraction Skills
Once you get comfortable with the process, here are a few tips to help you get faster and more accurate.
- Check Your Work: A great way to verify your answer is to use addition. Add your result to the number you subtracted. The sum should equal the number you started with. For our original problem:
4.74 (result) + 7.23 (subtracted number) = 11.97 (starting number).
Since it matches, our answer is correct! - Practice Mental Math: Try simple subtraction problems in your head. For example, when you’re at the store, calculate the discount on a sale item or estimate your final bill before you get to the register.
Final Answer
By following a simple, structured process, we can confidently determine the difference between what is the difference between 11.97 and 7.23. After aligning the decimal points and subtracting each column from right to left, the answer is 4.74.
Understanding how to perform basic math operations like subtraction is a valuable life skill that strengthens problem-solving abilities and helps in numerous daily activities.
Frequently Asked Questions
What is the most important step in subtracting decimals?
The most crucial step is to align the decimal points vertically before you begin subtracting. This ensures you are subtracting corresponding place values.
What if the numbers have a different number of decimal places?
If one number has more decimal places than the other, you can add placeholder zeros to the end of the shorter number. For example, to subtract 1.2 from 5.45, you would write it as 5.45 – 1.20.
How do you subtract a larger number from a smaller number?
When you subtract a larger number from a smaller one (e.g., 5 – 10), the result will be a negative number. You can find the difference between the two numbers (10 – 5 = 5) and then add a negative sign, making the answer -5.
