8th grade Math STAAR Practice Category 1 & 2

Front

What is the formula to calculate the total cost (y) based on the number of pounds of fudge (x) if 3 pounds cost $54.99?

Back

Front

How do you find the slope of a line representing a rate of change?

Back

The slope is calculated as the change in y over the change in x, often represented as \( m = \frac{\Delta y}{\Delta x} \).

Front

What is scientific notation and why is it used?

Back

Scientific notation is a way to express very large or very small numbers in the form of \( a \times 10^n \), where 1 ≤ a < 10 and n is an integer. It simplifies calculations and comparisons.

Front

How do you express the volume of salt water on Earth's surface, approximately 350,000,000,000,000,000,000 gallons, in scientific notation?

Back

Front

What does it mean for a value to be '6 less than the quotient of x and 4'?

Back

It means that if you divide x by 4 and then subtract 6, you get the value of y. This can be expressed as \( y = \frac{x}{4} - 6 \).

Front

What is a function in mathematics?

Back

A function is a relation that assigns exactly one output (y) for each input (x).

Front

How do you determine the value of x in an equation?

Back

To find the value of x, isolate x on one side of the equation using inverse operations.

Front

What is the relationship between the slope of a line and the rate of change?

Back

The slope of a line indicates the rate of change; a steeper slope means a greater rate of change.

Front

What is the meaning of 'leaking 0.8 gallons every 2 hours' in terms of slope?

Back

The slope represents the rate of leakage, which can be calculated as \( \frac{0.8 \text{ gallons}}{2 \text{ hours}} = 0.4 \text{ gallons per hour} \).

Front

How do you convert a fraction to a decimal?

Back

Divide the numerator by the denominator. For example, \( \frac{1}{4} = 0.25 \).