Place Value
The idea that a digit's position (like the ones, tens, or hundreds place) determines its value.
Example:
In the number 752, the '7' isn't just 7, it's 700 because it's in the hundreds place.
Value
How much a digit is worth based on its position.
Example:
In 345, the value of the '4' is 40.
Standard Form
The normal, everyday way we write numbers using digits.
Example:
1,234
Expanded Form
"Stretching out" a number to show the value of each digit added together.
Example:
For 345, it's 300 + 40 + 5.
Word Form
Writing a number out using only words, just like you would say it.
Example:
For 345, it's "Three hundred forty-five".
Rounding
Changing a number to a simpler, "friendlier" number that's close to the original value.
Example:
29 is close to 30. $8.99 is close to $9.00.
Estimation
Making a smart guess by rounding numbers *before* you add, subtract, etc. to get an "about" answer.
Example:
To solve 48 - 29, you estimate 50 - 30 = 20.
Fact Family
A group of 4 math facts (2 multiplication, 2 division) that use the same 3 numbers.
Example:
For 2, 5, 10:
2x5=10, 5x2=10, 10÷2=5, 10÷5=2
Inverse Operations
Opposite operations that "undo" each other.
Example:
Addition and Subtraction are inverses. Multiplication and Division are inverses.
Order of Operations
The set of rules (PEMDAS) that tells you which order to solve a math problem with multiple steps.
PEMDAS:
1. Parentheses
2. Exponents
3. Multiply/Divide (left to right)
4. Add/Subtract (left to right)