math 24-25

What operations can be performed with rational numbers?

Addition, subtraction, multiplication, and division.

What must be found to add or subtract fractions?

A common denominator.

How do you convert the fraction ( \frac{3}{4} ) to a decimal?

By dividing 3 by 4 to get 0.75.

How do you convert a decimal to a percentage?

Multiply by 100.

What does a proportion state?

That two ratios are equal, such as ( \frac{a}{b} = \frac{c}{d} ).

How can a proportion be solved?

By cross-multiplying.

What is the formula for the area of a rectangle?

( A = l \times w ), where ( l ) is the length and ( w ) is the width.

What do measures of central tendency include?

Mean, median, mode, and range.

What is the value of a in the expression ( a^2 )?

It represents a square number.

How do you find the circumference of a circle with a radius of 5 cm?

Use the formula ( C = 2\pi r ) to get ( C = 10\pi ).

What is the approximate circumference of a circle with a radius of 5 cm?

Approximately 31.4 cm.

How do you calculate the area of a circle with a radius of 3 cm?

Use ( A = \pi r^2 ) to get ( A = 9\pi ).

What is the approximate area of a circle with a radius of 3 cm?

Approximately 28.3 cm².

How do you find the circumference of a circle using the diameter?

Use the formula ( C = \pi d ).

If a circle has a diameter of 10 cm, what is its circumference?

( C = 10\pi ), approximately 31.4 cm.

What is the first step to find the area of a circle using the diameter?

Divide the diameter by 2 to find the radius.

How do you calculate the area of a circle with diameter 10 cm?

Calculate the radius as ( r = 5 ) and then use ( A = \pi r^2 ) to get ( A = 25\pi ).

What is the approximate area of a circle with a diameter of 10 cm?

Approximately 78.5 cm².