Chapter 25
Adding and Subtracting with Negatives Concept Explanation:
Adding and subtracting with negative numbers is crucial for mathematical fluency. The basic rules include:
- Adding a Negative Number: This is the same as subtracting the positive equivalent. For example, .
- Subtracting a Negative Number: This is the same as adding the positive equivalent. For example, .
Common Mistakes:
- Sign Confusion: Many students confuse adding and subtracting negative numbers; it’s essential to remember the rules.
- Neglecting Parentheses: When dealing with expressions, ensure that parentheses are properly used to indicate negative numbers.
Helpful Tips:
- Number Line Visualization: Use a number line to visualize the addition or subtraction of negative numbers.
- Practice with Word Problems: Real-life contexts can make the concept easier to grasp.
Hard Questions:
Q1: Calculate .
Step-by-Step Solution:
- Since you are adding a negative number, subtract instead:
Answer:
- The result is .
Q2: Calculate .
Step-by-Step Solution:
- Subtracting a negative is the same as adding:
Answer:
- The result is .
Q3: Calculate .
Step-by-Step Solution:
- Add the two negative numbers:
Answer:
- The result is .