Grade 10 Math
1. **Finding Volume of a Cylinder**
Problem: Calculate the volume of a cylinder with radius $r$ and height $h$.
Formula: $$V = \pi r^2 h$$
Explanation: The volume of a cylinder is the area of the circular base times the height.
Example: If $r=3$ and $h=5$, then $$V = \pi \times 3^2 \times 5 = 45\pi$$ cubic units.
2. **Finding Area of a Triangle**
Problem: Find the area of a triangle with base $b$ and height $h$.
Formula: $$A = \frac{1}{2} b h$$
Explanation: The area is half the product of the base and height.
Example: If $b=8$ and $h=6$, then $$A = \frac{1}{2} \times 8 \times 6 = 24$$ square units.
3. **Calculating Percentage Change**
Problem: Find the percentage change from an original value $O$ to a new value $N$.
Formula: $$\text{Percentage Change} = \frac{N - O}{O} \times 100\%$$
Explanation: Percentage change measures how much a quantity increases or decreases relative to the original.
Example: If $O=50$ and $N=65$, then $$\frac{65 - 50}{50} \times 100\% = 30\%$$ increase.
4. **Simplifying Algebraic Fractions**
Problem: Simplify the fraction $$\frac{2x^2 + 4x}{2x}$$.
Steps:
- Factor numerator: $$2x^2 + 4x = 2x(x + 2)$$
- Cancel common factor $2x$:
$$\frac{2x(x + 2)}{2x} = x + 2$$
Explanation: Canceling common factors simplifies the fraction.
5. **Basic Statistics - Mean**
Problem: Find the mean of the data set: 4, 8, 6, 10.
Formula: $$\text{Mean} = \frac{\text{Sum of values}}{\text{Number of values}}$$
Calculation: $$\frac{4 + 8 + 6 + 10}{4} = \frac{28}{4} = 7$$
Explanation: The mean is the average value.
These examples cover volume, area, percentage change, algebraic fractions, and statistics.