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Learn how to use the alligator mouths to show which three-digit number is bigger or smaller.
Imagine you are a hungry alligator who wants to eat the biggest snack possible. If you had to choose between a pile of 200 cookies or 500 cookies, which way would you open your mouth?
When we compare numbers, we use special symbols that look like an alligator's mouth. The alligator is very hungry, so his mouth always opens toward the bigger number!
1. Greater Than (): The mouth opens to the left because the first number is bigger. Example: . 2. Less Than (): The mouth opens to the right because the second number is bigger. Example: . 3. Equal To (): Used when both numbers are exactly the same. Example: .
Let's compare and . 1. Look at the numbers: and . 2. Which is bigger? is more than . 3. Draw the mouth opening toward . 4. Result: .
Quick Check
Which symbol would you use for and ?
Answer
The equal sign () because the numbers are the same.
To compare three-digit numbers, we use a secret trick: Start on the left! We look at the Hundreds place first. If one number has more hundreds, it is automatically bigger. If the hundreds are the same, we move to the Tens place. If those are the same too, we finally look at the Ones place. It's like a race where the hundreds get a head start!
Compare and . 1. Check Hundreds: Both have (). It's a tie! 2. Check Tens: Both have (). Another tie! 3. Check Ones: One has and the other has . Since , the number is bigger. 4. Result: .
Quick Check
If you compare and , which place value tells you the winner right away?
Answer
The Hundreds place ( is bigger than ).
Sometimes you have more than two numbers to compare. To put them in order from least to greatest (smallest to biggest), compare them two at a time. Find the smallest number first and put it at the start of your list. Then, compare the remaining numbers to see which comes next.
Put these in order from least to greatest: . 1. Compare hundreds: has the fewest hundreds (), so it is the least. 2. Compare and : Both have hundreds and ten. 3. Look at ones: is smaller than , so is smaller than . 4. Final Order: .
Which symbol makes this true?
Which number is the smallest?
The statement is true.
Review Tomorrow
Tomorrow morning, try to remember the three places we check in a 3-digit number. Which one do we check first?
Practice Activity
Look at three page numbers in a book. Try to write them down in order from smallest to biggest!