Learn to subtract three-digit numbers using place value! We'll subtract hundreds, tens, and ones separately, working column by column. It's like taking blocks away from a tower! 🏗️➖
Master three-digit subtraction with these engaging activities!
Learn what subtraction means and when to use it!
Practice subtracting each place value step by step!
🖱️ Drag options below to the correct boxes (computer) or click to move (mobile)
Apply your skills to solve real subtraction problems!
Learn to verify your subtraction answers using addition!
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Explore 7 comprehensive knowledge cards about subtraction strategies!
Subtraction is one of the four basic operations in math. We use it when we take things away, remove items, or want to find out how many are left. Think of it as the 'undo' button for addition - it takes you backwards! Understanding when to use subtraction is just as important as knowing how to do it.
Subtraction means 'taking away' or finding 'how many are left'
Example: 8 apples - 3 apples eaten = 5 apples left
It's the opposite of addition! If 5 + 3 = 8, then 8 - 3 = 5
Words that signal subtraction: take away, remove, left, difference, fewer, less
Subtraction answers the question 'How many remain?'
Look for key words in problems: 'left,' 'remain,' 'take away,' 'remove,' 'fewer,' 'less than,' or 'difference.' These words tell you to subtract!
Subtracting in the wrong order! In 589 - 123, you must subtract 123 FROM 589, not the other way around. The bigger number usually comes first.
Shopping (how much money left?), games (points lost), time (how long until?), measuring (how much more?), cooking (reducing amounts), and so much more!
Create subtraction stories from your day: 'I had 10 cookies, ate 3, how many left?' Real-life contexts make subtraction meaningful!
Just like with addition, we start subtraction with the ones place (rightmost column). Check if the top digit is bigger than or equal to the bottom digit. If yes, subtract and write the answer below! Without regrouping, this is straightforward - just subtract one digit from another.
789 - 456: Start with ones: 9 - 6 = 3
567 - 234: Ones column: 7 - 4 = 3
893 - 421: Subtract ones: 3 - 1 = 2
Always check: Is the top digit bigger than the bottom digit?
If yes, subtract straight down. If no, you'll need to regroup (next lesson!)
Before subtracting any column, glance quickly: 'Is the top number bigger?' This tells you if you can subtract without regrouping. Build this habit!
Subtracting smaller from larger without thinking! In 243 - 567, we can't do 3 - 7 without regrouping. Always check if subtraction is possible!
When you have 9 pencils and give away 6, you subtract in the ones place: 9 - 6 = 3 pencils left!
Practice single-digit subtraction until it's automatic: 9-3, 8-5, 7-2, etc. These are the building blocks for three-digit subtraction!
After subtracting ones, move left to the tens column. The process is identical - check if the top digit is bigger, then subtract! Remember, you're working with tens (multiples of 10), so 8 - 5 in the tens column means 80 - 50 = 30, and you write 3 in the tens place.
789 - 456: After ones, subtract tens: 8 - 5 = 3 (that's 80 - 50 = 30)
567 - 234: Tens column: 6 - 3 = 3 (60 - 30 = 30)
893 - 421: Subtract tens: 9 - 2 = 7 (90 - 20 = 70)
Remember: You're subtracting tens, not ones!
The digit 8 in the tens place represents 80, not 8
Think 'drop the zeros, subtract, then remember they're tens!' For 80 - 50: think 8 - 5 = 3, but remember it's 3 tens, or 30!
Forgetting the place value! In the tens column, 8 - 5 doesn't equal 3 ones, it equals 3 tens (30). Place value matters!
Money! If you have 8 dimes (80¢) and spend 5 dimes (50¢), you have 3 dimes (30¢) left. That's subtracting in the tens place!
Practice 'tens subtraction': 80-50, 90-30, 70-40. Get comfortable with these before tackling full three-digit problems!
The final step is subtracting the hundreds column (leftmost digits). By now, you've mastered the pattern! Check if the top digit is bigger, then subtract. Remember you're working with hundreds, so 7 - 4 means 700 - 400 = 300, and you write 3 in the hundreds place!
789 - 456: Finally, subtract hundreds: 7 - 4 = 3 (700 - 400 = 300)
567 - 234: Hundreds: 5 - 2 = 3 (500 - 200 = 300)
893 - 421: Subtract hundreds: 8 - 4 = 4 (800 - 400 = 400)
This is the last step in three-digit subtraction!
Hundreds are the biggest place value we're working with
Same pattern as tens: 'drop the zeros, subtract, remember it's hundreds!' For 700 - 400: think 7 - 4 = 3, but it's 3 hundreds = 300!
Rushing through and forgetting to subtract each column! Take your time and work through ones, tens, then hundreds systematically.
Large amounts of money! If you have $700 and spend $400, you have $300 left. That's subtracting in the hundreds place!
Practice 'hundreds subtraction': 800-500, 900-300, 700-200. Master this and three-digit subtraction becomes easy!
The best way to check subtraction is to use addition! Since subtraction and addition are opposite operations, if your subtraction is correct, adding the answer and the subtracted number should give you the original number. This is like a math 'proof' that your answer is right!
If 589 - 123 = 466, check: does 466 + 123 = 589? Yes! ✓
If 789 - 456 = 333, check: does 333 + 456 = 789? Yes! ✓
Addition and subtraction are inverse operations - they undo each other!
Think: 'answer + what I subtracted = original number'
If your check doesn't work, recheck your subtraction!
Always write your check: '466 + 123 = 589 ✓' This way you have evidence your answer is correct. Get in the habit of checking EVERY subtraction problem!
Not checking your work! Or checking but ignoring when it doesn't match. If your check fails, don't ignore it - that's your signal to recheck!
Banking and money! If you had $589, spent $123, and think you have $466 left, you can verify: $466 + $123 should equal $589. Banks do this constantly!
Make checking a game: 'I bet you can't check all your answers correctly!' Challenge makes verification fun rather than tedious.
Vertical (column) subtraction is the standard format because it keeps place values perfectly aligned! When everything lines up correctly, you can't accidentally subtract wrong places. Always check alignment before you start - good organization prevents mistakes!
Write the larger number on top, smaller number below
Line up place values: ones under ones, tens under tens, hundreds under hundreds
Draw a line under the bottom number
Subtract each column from right to left
Write your answer below the line
Use graph paper or make columns with a ruler! Perfect alignment makes subtraction so much easier. This is especially important as you work with larger numbers.
Sloppy writing that makes digits drift out of alignment. If your 5 and 2 aren't perfectly lined up vertically, you might subtract from the wrong place!
This is how subtraction is written everywhere - in stores, banks, schools, tax forms, receipts, and any time people write out subtraction. Learn it once, use it forever!
Practice lining up numbers: Write horizontal problems (589 - 123) in vertical format. Perfect alignment is a skill that needs practice!
Three-digit subtraction is everywhere in daily life! Any time you need to find 'what's left,' 'how many remain,' or 'the difference between' two amounts, you use subtraction. Recognizing real-world subtraction situations helps math make sense and shows why these skills are valuable!
Shopping: You have $589, spend $123, have $466 left 💰
Library: 765 books total, 432 checked out = 333 books on shelves 📚
Games: Started with 987 points, lost 543 points = 444 points left 🎮
Travel: 879 miles total trip, drove 456 miles = 423 miles to go 🚗
School: 598 students total, 234 at lunch = 364 still in classrooms 🏫
Look for 'comparison' situations too! 'How much taller,' 'how many more,' 'what's the difference' - these all mean subtraction, even though nothing is being 'taken away!'
Not recognizing when a problem needs subtraction! Watch for keywords: left, remain, difference, fewer, less, how many more, how much taller. These signal subtraction!
Budgeting money, tracking inventory, measuring differences, comparing scores, calculating remaining amounts, and planning are all real subtraction uses!
Create personal word problems! 'My town has 845 people, 312 are kids, how many adults?' Math from your life is more meaningful!