Saving For A Watch: How Much More Does Lenna Need?
Hey guys! Let's dive into a fun math problem today. We're going to help Lenna figure out how much more money she needs to save to buy that awesome wristwatch she's been eyeing. It's a classic subtraction problem, but let's break it down step-by-step so it's super clear. Understanding these kinds of financial calculations is really important in the real world, so pay close attention!
Understanding the Problem
Okay, so first things first, let's understand what we know. Lenna, our little saver, has already managed to squirrel away $125. That's a great start! Now, the object of her desire, that shiny wristwatch, comes with a price tag of $9,315. That's a bit more than she has right now. So, the question we need to answer is: how much more money does Lenna need to save to reach her goal? This “how much more” is a big clue that we're dealing with a subtraction problem. We need to find the difference between the cost of the watch and the amount Lenna has already saved. Imagine it like this: the total amount she needs is $9,315, and she’s already got $125 covered. We need to figure out what’s left. We can also think of this as finding the missing piece of a puzzle. We have one piece ($125), we know the whole picture ($9,315), and we need to find the other piece.
To recap, the key information here is:
- Amount Lenna has saved: $125
- Cost of the wristwatch: $9,315
And the question we're trying to answer is:
- How much more money does Lenna need to save?
Now that we've got a clear picture of the problem, let's move on to the fun part: solving it!
Setting Up the Subtraction
Alright, let's get down to the math! We know we need to subtract the amount Lenna has saved ($125) from the cost of the wristwatch ($9,315). This will tell us the difference, which is how much more she needs to save. Setting up the subtraction is crucial to get the right answer. Think of it like building a house – you need a solid foundation! We're going to write the larger number, $9,315, on top. This is because we're taking away a smaller amount from it. Then, we write the smaller number, $125, underneath, making sure to line up the digits according to their place value. This means the ones digits (5 and 5) are in the same column, the tens digits (1 and 2) are in the same column, and so on. Proper alignment is super important, guys! If you don't line up the digits correctly, your answer will be off. It's like mixing up your ingredients in a recipe – you might end up with a cake that tastes like pizza! So, double-check that everything is lined up neatly.
Our setup should look like this:
9315
- 125
------
See how the 5 in $9,315 and the 5 in $125 are in the same column (the ones column)? The 1 in $9,315 and the 2 in $125 are in the same column (the tens column), and so on. Now that our foundation is solid, we're ready to subtract!
Performing the Subtraction
Okay, time to subtract! We're going to work column by column, starting from the rightmost column (the ones column) and moving to the left. In the ones column, we have 5 - 5. That's easy peasy – 5 minus 5 is 0. So, we write a 0 in the ones place in our answer. Next, we move to the tens column. Here, we have 1 - 2. Uh oh! We can't subtract 2 from 1, can we? We don't have enough tens to take away 2. This is where borrowing comes in handy! We need to borrow 1 hundred from the hundreds column. The 3 in the hundreds column becomes a 2, and the 1 in the tens column becomes 11 (because we're borrowing 10 tens). Now we have 11 - 2, which is 9. So, we write a 9 in the tens place in our answer. Moving on to the hundreds column, we now have 2 - 1 (remember, we borrowed 1 from the 3). 2 minus 1 is 1, so we write a 1 in the hundreds place. Finally, we get to the thousands column. We have a 9, and since there's no digit to subtract below it, we just bring the 9 down. Now, let's take a look at our result. We should have something like 9190. Let's write it out nicely:
9315
- 125
------
9190
So, it looks like Lenna needs to save $9,190 more to buy her wristwatch! But before we jump to conclusions, let's double-check our work to make sure we didn't make any silly mistakes.
Checking the Answer
Always, always, always check your answer, guys! It's like proofreading an essay – you might catch a mistake you didn't see before. The easiest way to check a subtraction problem is to use addition. We can add the amount Lenna has saved ($125) to the amount we think she still needs ($9,190). If the result equals the cost of the wristwatch ($9,315), then we know we've got the right answer! Let's set up the addition problem:
9190
+ 125
------
Starting from the ones column, we have 0 + 5, which is 5. In the tens column, we have 9 + 2, which is 11. We write down the 1 and carry over the other 1 to the hundreds column. In the hundreds column, we have 1 (carried over) + 1 + 1, which is 3. Finally, in the thousands column, we have 9, and there's nothing to add to it, so we just bring it down. Our result is $9,315. Hooray! That's the cost of the wristwatch, so we know we did the subtraction correctly. Checking your work isn’t just about getting the right answer in a math problem. It's a good habit to develop in all areas of life. It helps you catch errors, avoid mistakes, and build confidence in your work. Think of it as giving your work a final polish before you present it to the world.
Conclusion: Lenna's Savings Goal
Alright, guys, we did it! We helped Lenna figure out how much more money she needs to save. By subtracting the amount she has already saved from the cost of the wristwatch, we found that Lenna needs to save an additional $9,190. That's a pretty big number, but with a little hard work and dedication, Lenna can definitely reach her goal! This problem highlights the importance of financial literacy. Understanding how to calculate savings, costs, and differences is a crucial skill for everyone. Whether you're saving up for a new gadget, a vacation, or even a down payment on a house, these basic math skills will help you manage your money wisely. So, let's give Lenna a virtual high-five and wish her good luck on her savings journey! And remember, guys, math isn't just about numbers and equations – it's about solving real-world problems and achieving your goals. Keep practicing, keep learning, and you'll be amazed at what you can accomplish!