SBAC Grade 8 Math Practice Test 1

Question 1

The total length of the world's coastlines is about 315,000 miles. Which answer expresses this in scientific notation?

Accepted Answer

3.15×〖10〗^5

Answer

Scientific notation expresses a number as a product of a number between 1 and 10 and a power of 10. To convert 315,000, move the decimal point from the end of the number to after the first non-zero digit (3). The decimal point moves 5 places to the left, so the exponent of 10 is 5, resulting in 3.15 × 10^5.

Question 2

John’s Gym charges its members according to the equation C=40m where m is the number of months and C represents the total cost to each customer after m months. Ralph’s Recreation Room charges its members according to the equation C=45m. What relationship can be determined about the monthly cost to the members of each company?

Accepted Answer

John’s monthly membership fee is less than Ralph’s monthly membership fee.

Answer

In the given equations, C=40m for John's Gym and C=45m for Ralph's Recreation Room, the coefficient of 'm' represents the monthly membership fee. For John's Gym, the monthly fee is $40, and for Ralph's Recreation Room, it is $45. Since $40 is less than $45, John's monthly membership fee is less than Ralph's.

Question 3

Which of the following graphs is not a function?

Accepted Answer

D.

Answer

A graph represents a function if it passes the vertical line test, meaning any vertical line drawn through the graph intersects it at most once. Graph D fails this test because a vertical line can intersect it at multiple points. This indicates that for a single x-value, there are multiple y-values, which is not permitted in a function.

SBAC Practice Test

SBAC Practice Test

SBAC Grade 8 Math Practice Test 1