Addition and Subtraction Basics

Definition: Combining two or more quantities to get a total.
Symbols: Represented by the plus sign (+).
Properties:
- Commutative Property: a + b = b + a (order doesn't matter).
- Associative Property: (a + b) + c = a + (b + c) (grouping doesn't matter).
- Identity Property: a + 0 = a (adding zero does not change the value).
Types:
- Single-digit addition: e.g., 3 + 4 = 7.
- Multi-digit addition: e.g., 56 + 78 involves carrying over.
Mental Strategies:
- Break apart numbers (e.g., 29 + 34 → 20 + 30 + 9 + 4).
- Use of number lines to visualize.

Definition: Finding the difference between two quantities.
Symbols: Represented by the minus sign (−).
Properties:
- Non-commutative: a - b ≠ b - a (order matters).
- Associative Property does not apply: (a - b) - c ≠ a - (b - c).
- Identity Property: a - 0 = a (subtracting zero does not change the value).
Types:
- Single-digit subtraction: e.g., 7 - 4 = 3.
- Multi-digit subtraction: e.g., 82 - 47 involves borrowing.
Mental Strategies:
- Count up to find the difference.
- Use benchmarks (rounding numbers to simplify calculations).

Both operations are fundamental arithmetic skills necessary for more complex mathematical concepts.
Practice with real-life applications helps to reinforce addition and subtraction skills (e.g., budgeting, cooking measurements).

Combining two or more quantities results in a total.
Represented by the plus sign (+).
Commutative Property: The order of addition does not affect the sum (e.g., a + b = b + a).
Associative Property: The way numbers are grouped does not change the sum (e.g., (a + b) + c = a + (b + c)).
Identity Property: Adding zero to a number does not change its value (e.g., a + 0 = a).
Types:
- Single-digit addition: Simple calculations (e.g., 3 + 4 = 7).
- Multi-digit addition: Involves carrying over values (e.g., 56 + 78).
Mental Strategies:
- Break apart numbers for easier calculation (e.g., 29 + 34 → 20 + 30 + 9 + 4).
- Use a number line to visualize the addition process.

A method to find the difference between two quantities.
Represented by the minus sign (−).
Non-commutative: The order of subtraction matters (e.g., a - b ≠ b - a).
Associative Property does not apply: The grouping of numbers can change the outcome (e.g., (a - b) - c ≠ a - (b - c)).
Identity Property: Subtracting zero from a number maintains its value (e.g., a - 0 = a).
Types:
- Single-digit subtraction: Simple calculations (e.g., 7 - 4 = 3).
- Multi-digit subtraction: Involves borrowing values (e.g., 82 - 47).
Mental Strategies:
- Count up from the smaller number to find the difference.
- Use benchmarks by rounding numbers to simplify the calculation.

Addition and subtraction are fundamental arithmetic skills essential for understanding more complex mathematical concepts.
Practicing these operations through real-life applications, such as budgeting and cooking measurements, enhances skills and conceptual understanding.

Definition: Combining two or more numbers to achieve a total.
Symbol: Plus sign represented as (+).
Properties:
- Commutative Property: The order of numbers does not affect the sum (a + b = b + a).
- Associative Property: Grouping of numbers does not alter the result ((a + b) + c = a + (b + c)).
- Identity Property: Adding zero to a number does not change its value (a + 0 = a).
Types:
- Single-Digit Addition: Focuses on operations with numbers between 0 and 9.
- Multi-Digit Addition: Involves larger numbers and may require carrying over.
- Mental Math: Involves quick calculations done mentally without written aids.
Examples:
- Simple addition: 3 + 5 equals 8.
- Larger numbers: 12 + 15 equals 27.

Definition: Taking one number away from another to determine the difference.
Symbol: Minus sign shown as (−).
Properties:
- Non-Commutative: Changing the order of numbers affects the outcome (a - b ≠ b - a).
- Identity Property: Subtracting zero from a number does not alter its value (a - 0 = a).
- Inverse Relationship: Subtraction is the inverse operation of addition (a - b is related to a + b).
Types:
- Single-Digit Subtraction: Basic operations with numbers 0-9.
- Multi-Digit Subtraction: Involves larger numbers, may require borrowing.
- Negative Results: Occurs when the first number is smaller than the second, resulting in a negative difference.
Examples:
- Basic operation: 8 - 3 equals 5.
- Larger operation: 15 - 7 equals 8.