Three-Digit Subtraction Input/Output Tables
Start Practice

## How to Use 3-Digit Subtraction Input/Output Tables

At an arcade, you use tickets to buy your favorite candy. Each candy bar costs 120 tickets. On your first game, you earned 215 tickets. Out of these tickets, you bought 1 candy bar. In the next game, you earned 180 tickets and bought 1 more candy bar. You played once more and earned 350 tickets. Then you bought 1 more candy bar. How many tickets did you have left over after buying each candy?

How can we solve this problem? 🤔

We have to subtract 120 tickets from each total! ✅

120 tickets is the cost of 1 candy.

Since we are subtracting the same number so many times, we can keep track of the number of tickets left in an input/output table.

### Input/Output Tables

Do you remember what an Input/Output table is? 🤓

An input/output table is a table with 2 columns - In and Out, where the numbers in the first column follow a common rule to give numbers in the second column.

This is an input/output table. 👇

Let us fill this table according to our example.

✅ First we fill the In column.

Which numbers should go in there? 🤔

Correct! 😃

Our ins are going to be the tickets you earned for each game: 215, 180, 350.

Let’s put those in the “In” column:

✅ Now, let us find the rule for this table.

According to the problem, what should happen to each number in the first column? 🤓

That's right!

We subtract 120 tickets from each number, because this is how much a candy costs.

So, the rule for this input/output table is:

Subtract 120

✅ Now, let us fill the Out column.

In this case, the output will be the total tickets after you subtract 120.

215 - 120 = 95

Now, we’ll put 95 in the first “Out” spot.

Let’s do the next one!

180 - 120 = 60

Great! Now, put 60 in the second "Out" spot.

Can you do the last one?

Great job!! 😎

### Another Example

😃 Let’s try another example.

Here’s an input/output table:

✅ The rule is:

Subtract 312

Let’s try the first one together.

470 - 312 = 158

Let’s put 158 in the first “Out” spot.

Can you do the rest of them? 🤔

You got it!! 🤗

Great job on the lesson! 👏 Now, you can move on to the practice!

### Lesson Streak

0 days
Complete the practice every day to build your streak
W
T
F
S
S
M
T
Start Practice
Complete the practice to earn 1 Create Credit

1,000 Create Credits is worth \$1 in real AI compute time.

1 Create Credit is enough to get 1 question answered, or to generate 1 image from text, in the tools tab.
Teachers:
Assign to students
Duplicate
Edit Questions
Edit Article
Assign
Preview Questions
Edit
Duplicate
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "url": "https://www.classace.io/learn/math/2ndgrade/three-digit-subtraction-io-tables", "fetch_time": 1709128533000000000, "content_mime_type": "text/html", "warc_filename": "crawl-data/CC-MAIN-2024-10/segments/1707947474715.58/warc/CC-MAIN-20240228112121-20240228142121-00851.warc.gz", "warc_record_offset": 712117206, "warc_record_length": 32293, "token_count": 691, "char_count": 2612, "score": 4.15625, "int_score": 4, "crawl": "CC-MAIN-2024-10", "snapshot_type": "latest", "language": "en", "language_score": 0.8918850421905518, "file_path": "/sailhome/yjruan/project/latent-lm/data/processed/finemath-4plus/finemath-4plus/train-00009-of-00064.parquet"}