Three Digit Subtraction with Regrouping - Expanded Form
Basics on the topic Three Digit Subtraction with Regrouping - Expanded Form
Subtraction with Regrouping – Expanded Form
What is the expanded form in subtraction? Expanded form is a way to write a number that emphasizes the value each digit holds. In a subtraction equation, we can write each number in expanded form to make regrouping easier. Look at the number 678 in expanded form in the illustration below.
Subtraction with Regrouping and Expanded Form – Example
Let’s use the example eight hundred fifty minus ninety-nine to model our steps. First, write eight hundred fifty and ninety-nine in expanded form with the larger number on top. We'll put separation lines in place of the addition signs, so we don't confuse ourselves as we subtract.
Then, we subtract the ones column: zero minus nine. Since we cannot subtract from zero, we will regroup a ten from the tens place. Now, we subtract ten minus nine. Write the difference, one, below.
Then, we subtract the tens column, forty minus ninety. Since there is not enough to subtract from, we regroup one hundred from the hundreds place. We can now subtract: one hundred forty minus ninety. Write the difference, fifty, below.
Next, we subtract the hundreds column: seven hundred minus zero. We write the difference, seven hundred, below. Finally, put the answer back in standard form by adding it together. Seven hundred plus fifty plus one becomes seven hundred fifty-one.
Subtraction with Regrouping and Expanded Form – Summary
Remember, we can write each number in a subtraction equation using expanded form to make regrouping easier.
| Step # | What to do |
|---|---|
| 1 | Subtract the ones column. If there is not enough to subtract from, regroup a ten from the tens place and subtract. |
| 2 | Move to the tens and the hundreds place repeating this process as necessary. |
| 3 | Put the answer back in standard form by adding it together. |
First, subtract the ones column. If there is not enough to subtract from, regroup a ten from the tens place and subtract.
Then, move to the tens and the hundreds place repeating this process as necessary.
Finally, put the answer back in standard form by adding it together.
Have you practiced yet? After watching the video, you can also find more interactive exercises, worksheets and more activities for 3-digit subtraction in expanded form.
Transcript Three Digit Subtraction with Regrouping - Expanded Form
Mr. Squeaks and Imani are ready to play on their devices, but nothing will load! "Did we run out of data, Imani?" "Let's check our devices to see if there's any left." However, they are having trouble subtracting from three digit numbers. Let's help Imani and Mr. Squeaks solve their equations by learning "Three Digit Subtraction with Regrouping - Expanded Form". Expanded form is a way to write a number that emphasizes the value each digit holds. In a subtraction equation, we can write each number in expanded form to make regrouping easier. Let's check Mr. Squeaks data usage to practice. It says he has eight hundred fifty megabytes of data and used ninety-nine, how much data is left? First, write eight hundred fifty and ninety-nine in expanded form with the larger number on top. We'll put separation lines in place of the addition signs, so we don't confuse ourselves as we subtract. Then, subtract the ones column: zero minus nine. Since there is not enough to subtract from, regroup a ten from the tens place. Now subtract ten minus nine. Write the difference, one, below. Then, subtract the tens column, forty minus ninety. Since there is not enough to subtract from, regroup one hundred from the hundreds place and subtract, one hundred forty minus ninety. Write the difference, fifty, below. Subtract the hundreds column, seven hundred minus zero, and write the difference, seven hundred, below. Finally, put the answer back in standard form by adding it together, seven hundred fifty-one. Huh, Mr. Squeaks should have seven hundred fifty one megabytes of data left. Now, Imani checks their data usage. It says Imani has three hundred megabytes of data and used two hundred ninety-nine..how much data is left? What should we do first? First, write three hundred minus two hundred ninety-nine in expanded form like this. Do you know our next step? Next, subtract the ones column, but we cannot take nine away from zero so regroup a ten from the tens place and subtract, but there is nothing we can borrow since there is zero there. Where can we regroup from? We can regroup one hundred from the hundreds column. Now that there is a hundred to borrow from in the tens place, we can take a ten to regroup for the ones place. Where should we subtract now? The ones place. Ten minus nine is one and we write the difference, here. Then, we move to the tens place and subtract ninety from nine to get zero. Finally, subtract the hundreds place: two hundred minus two hundred equals zero. What is our very last step? Put the answer back in standard form by adding it together, one! Huh, Imani still has one megabyte of data left! Before we solve the data dilemma, let's summarize! Remember, we can write each number in a subtraction equation using expanded form to make regrouping easier. First, subtract the ones column. If there is not enough to subtract from, regroup a ten from the tens place and subtract. Then, move to the tens and the hundreds place repeating this process as necessary. Finally, put the answer back in standard form by adding it together. "I just don't get it, Imani we should both have enough data left to keep playing." "Umm, Mr. Squeaks, I think I forgot to unplug my bed… and plug in the wifi."
Three Digit Subtraction with Regrouping - Expanded Form exercise
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What is expanded form?
HintsNumbers can be written using expanded form!
Here is a number in expanded form. You can see each digit's value is shown.
SolutionExpanded form is a way to write a number that emphasizes the value each digit holds. In a subtraction equation, this makes regrouping easier.
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Which number is correctly written in expanded form?
HintsCompare this correctly expanded number to the options you have to choose from.
Remember, the value of each digit should be emphasized. If a number is in the hundreds, the first digit should be in the hundreds in the expanded form.
SolutionThe correctly expanded 321 is 300 + 20 + 1. The value of each digit is clear so that when it comes time to subtract, it will be easier!
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How much data does Mr. Squeaks have left after phone calls?
HintsRemember, you may need to regroup from the tens or hundreds column to be able to subtract correctly.
You will have to regroup from the tens column to solve this problem.
SolutionOnce you regroup ten from the tens place you are able to subtract the numbers. Once you do that, you will see that Mr. Squeaks has 643 megabytes of data left after making his phone calls.
In the ones place, ten minus seven is three. Since we regrouped from the tens column to subtract in the ones column, 40 minus zero is 40. Finally, 800 minus 200 is 600 leaving us with the final answer 643.
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How much data did Imani use watching videos online?
HintsTake a look at the problem in the expanded form!
You will need to regroup from the hundreds and tens place to correctly solve this equation.
SolutionAs you can see here, using the expanded form helps when we have to regroup numbers. Once we regrouped from everywhere necessary and solved the equation, we found out that Imani has 385 megabytes of data left after watching videos online!
First, after regrouping from the tens column, 10 minus 5 equals five. Again, we have to regroup from the hundreds column to get the answer for the tens column (140-60=80). Finally, we are left with 700 minus 400 leaving us with 300 in the hundreds column.
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How much data is left?
HintsIn this problem you don't have to regroup any numbers, just subtract the numbers provided.
Remember to start from the ones column and move to the tens place then the hundreds place.
SolutionNewton has 233 megabytes of data left. Since this problem didn't require any regrouping, you could just subtract each of the expanded numbers individually!
In the ones place, five minus two is three. In the tens place, 50 minus 20 is 30. Lastly, in the hundreds place, 400 minus 200 is 200. Then recombine the digits to get the answer!
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How much data is left for Mr. Squeaks?
HintsRemember, the larger number should be on top of the equation.
Take a look at the expanded form of Mr. Squeak's problem here!
SolutionMr. Squeaks has 681 megabytes of data left after playing the video game. To find the answer, we subtracted the amount of data used (71 megabytes) from the total Mr. Squeaks had left (751 megabytes). This left us with 681 megabytes.
No regrouping is needed in the ones column to subtract zero from 1. We do need to regroup in the tens column from the hundreds column, however. Once done we subtract 150 minus 70 which equals 80. Finally, we have 600 minus zero in the hundreds column where we are still left with 600.
