Full-Length 8th Grade SBAC Math Practice Test-Answers and Explanations

Did you take the 8th Grade SBAC Math Practice Test? If so, then it’s time to review your results to see where you went wrong and what areas you need to improve.

8th Grade SBAC Math Practice Test Answers and Explanations

1- Choice C is correct
Jason ate \(\frac{1}{2}\) of 8 parts of his pizza. It means 4 parts out of 8 parts (\(\frac{1}{2}\) of 8 parts is \(x ⇒ x=4\)) and left 4 parts. Eva ate \(\frac{3}{4}\) of 8 parts of her pizza. It means 6 parts out of 8 parts (\(\frac{3}{4}\) of 8 parts is \(x ⇒ x=6\)) and left 2 parts.
Therefore, they ate (4 + 6) parts out of (8 + 8) parts of their pizza and left (4 + 2) parts out of (8 + 8) parts of their pizza that equals to: \(\frac{6}{16}\)
After simplification, the answer is: \(\frac{3}{8}\)

2- The answer is \(5 \frac{7}{10}\) miles.
Robert runs \(3 \frac{1}{10}\) miles on Saturday and \(2×(3 \frac{1}{10} )\) miles on Monday and Wednesday.
Robert wants to run a total of 18 miles this week.
Therefore: \(3 \frac{1}{10}+2×(3 \frac{1}{10})\) should be subtracted from 18:
\(18-(3\frac{1}{10}+2(3 \frac{1}{10}))=15-9 \frac{3}{10}=5 \frac{7}{10}\) miles.

3- Choice A is correct
Let \(x\) be the integer. Then: \(2x+20=68\). Subtract 20 from both sides: \(2x=48\). Divide both sides by \(2\) ⇒ \(x=24\)

4- The answer is: –37
Use PEMDAS (order of operation):
\([3×(–21)+(5×2)]–(–25)+[(–3)×6]÷2=[-63+10]+25+[-18]÷2=-53+25-9=-37\)

5- The answer is 768 cm.
Write the proportion and solve for missing side.
\(\frac{Smaller \space triangle \space height}{Smaller \space triangle \space base}
=\frac{Bigger \space triangle \space height}{Bigger \space triangle \space base} ⇒ \frac{100 \space cm}{160 \space cm}=\frac{100+380 \space cm}{x}⇒ x=768 \space cm\)

6- Choice C is correct.
Write the proportion and solve. \(\frac{3 \space ft}{2 \space ft}= \frac{x}{38 \space ft} ⇒ x=57 \space ft\)

7- Choice D is correct.
The distance that Mike runs can be found by the following equation:
\(D_M= 5.5t+7.5\). The distance Julia runs can be found by \(D_J=8t\)
Julia catches Mike if they run the same distance. Therefore:
\(8t=5.5t+7.5⇒2.5t=7.5 ⇒t= \frac{7.5}{2.5}=3\) hours

8- Choice C is correct
x is the number of all sales profit and \(2\%\) of it is:
\(2\%×x=0.02x\). Employer’s revenue: \(0.2x+7,000\)

9- The answer is 60.
Jason needs a \(75\%\) average to pass the exams. Therefore, the sum of 5 exams must be at least \(5×75=375\). The sum of 4 exams is: \(68+72+85+90=315\).
The minimum score Jason can earn on the final test to pass is: \(375-315=60\)

10- Choice C is correct.
We can write: \(\frac{25}{100}=\frac{8}{x}⇒\frac{8×100}{25}=x⇒x=32\)

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\\5x+10y=20\end{cases}\)
⇒Add two equations
\(-10y=-30→y=3\) , plug in the value of \(y\) into the first equation
\(x+4y=10⇒x+4(3)=10⇒x+12=10\)
Subtract 12 from both sides of the equation. Then: \(x+12=10→x=-2\)

15- Choice B is correct.
\(\frac{21+18+16+x}{4} =20⇒\frac{55+x}{4}=20⇒55+x=80⇒x=25\)

16- Choice B is correct.
Solve for \(x\).
\(5≤3x-1<11\)⇒ (add 1 all sides) \(5+1≤3x-1+1<11+1 ⇒ 6≤3x<12\) ⇒ (divide all sides by 3) \(2≤x<4 ⇒x\) is between 2 and 4.

17- Choice D is correct.
Distance between two points is equal: \(\sqrt{(x_1-x_2)^2+(y_1-y_2)^2} =\sqrt{(13-(-2)^2+(-2-6)^2}=\sqrt{15^2+(-8)^2}=\sqrt{225+64}=\sqrt{289}=17\)

18- Choice B is correct
The distance between two points is equal:
\(\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}=\sqrt{(9-4)^2+(7-(-5)^2}=\sqrt{(5)^2+(-12)^2}=\sqrt{169}=13\)

19- Choice D is correct
The slop of line A is: \(m=\frac{y_2-y_1}{x_2-x_1}=\frac{-10-8}{4-(-8)}=-\frac{3}{2}\)
Also \((y-y_1 )=m(x-x_1 )⇒y-8=-\frac{3}{2}(x+8)⇒y=-\frac{3}{2} x-4\)

20- Choice C is correct
The value of \(y\) in the \(x\)-intercept of a line is zero. Then:
\(y=0→10x-4(0)=5→10x=5→x=\frac{1}{2}\). Then, \(x\)-intercept of the line is \(\frac{1}{2}\)

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21- Choice C is correct
The total amount of money Giselle made as a carpenter can be modeled by \(20x\), and the total amount of money she made as a blacksmith can be modeled by \(25y\). Since these together add up to $690, we get the following equation:
\(20x+25y=690\).
We are also given that last week, Giselle worked as a carpenter and a blacksmith for a total of 30 hours. This can be expressed as:
\(x+y=30⇒y=30-x\)
Therefor \(20x+25(30-x)=690⇒x=12\) and \(y=18\)

22- Choice D is correct
\(\begin{cases}3x+y=8\\-5x-2y=0\end{cases}\)
Multiply the top equation by 2 then,
\(\begin{cases}6x+2y=16\\-5x-2y=0\end{cases}\)
⇒ Add two equations
\(x=16\) , plug in the value of \(y\) into the first equation
\(3x+y=8→3(16)+y=8→y=-40\)

23- Choice D is correct
Let \(x=\) the total miles of the ride.
Therefore, \(x-1=\) the additional miles of the ride. The correct equation takes $1.25 and adds it to $1.15 times the number of additional miles, \(x-1\). Translating, this becomes: \(y\)(the total cost)\(=1.25+1.15(x-1)\), which is the same equation as \(y=1.15(x-1)+1.25\).

24- Choice D is correct.
Write as two points in terms of: (number of people, cost in$) (15,120) and (25,200). Find the equation of the line using: m\(=\frac{y_2-y_1}{x_2-x_1}\) and \(y=mx+b\)
Equation: \(y=8x\) plug in \(x=40\), \(y=8(40)=320\). A party of 40 people will cost $320.00.

25- Choice A is correct
\(C=250+150h\). Assuming the initial meeting counts for the 1st hour, you would plug in \(h=25\) for a total cost of $4000.00.

26- Choice D is correct
Let the number be \(x\). Then the other number\(=x+8\). Sum of two numbers \(=30\). According to question, \(x+x+8=30 ⇒2x+8=30⇒ 2x=22⇒ x=11\). Therefore, \(x+8=11+8=19\)

27- Choice C is correct.
\(0.0000005823=5.823 × 10^{-7}\)

28- Choice B is correct.
\(28,000,000,000=2.8×10^{10}\)

29- Choice B is correct.
The area of greater circle is: \(A_g=πr^2=π .(45)^2=6361.7 \space mm^2\)
The area of smaller circle is: \(A_s=πr^2=π .(33)^2=3421.2 \space mm^2\)
Then area of colored part is \(A_c=A_g-A_s=6361.7-3421.2=2940.5 \space mm^2\)

30- Choice C is correct.
When a point is reflected over the y-axis, the \((x)\) coordinate of that point changes to \((-x)\), while its y coordinate remains the same.

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Frequently Asked Questions

What is the SBAC test?

The Smarter Balanced Assessment Consortium (SBAC) test is a Common Core-aligned annual state test used by many states including California, Washington, Oregon, Hawaii, Idaho, Nevada, Connecticut, Delaware, Vermont, South Dakota, and Montana. It covers ELA and math in grades 3-8 and 11.

How should we use a practice test and its explanations?

First, take the test under realistic conditions. Score it the same day. Then go through every wrong answer (and every uncertain right answer) with the explanation — rewrite the solution, name the concept, and write a one-sentence reminder.

What 8th grade math topics does SBAC cover most?

Linear equations and functions, systems of equations, the Pythagorean Theorem, rigid transformations and dilations, volume of cylinders/cones/spheres, scatter plots and lines of best fit, and basic function notation.

How long is the 8th grade SBAC math test?

About 2-2.5 hours across two main sessions, plus a performance task that takes an additional 30-60 minutes. Most schools split the test over two or three days.

Is the SBAC adaptive?

The computer-adaptive portion is — the algorithm adjusts difficulty based on prior answers. The performance task is fixed and asks students to work through a multi-step problem with real-world context.

Are calculators allowed on 8th grade SBAC?

Yes — an embedded online scientific calculator is available on most items. Some early items are calculator-prohibited. Practice with the actual on-screen calculator interface before test day.

How is the SBAC scored?

Performance is reported in four achievement levels (Level 1 through Level 4). Levels 3 and 4 indicate the student is on track for the next grade.

What is the most efficient review strategy?

Group your wrong answers by topic. If three items missed all involved slope, that’s a clear study target. If misses are scattered, the issue is more likely careful reading than content knowledge — practice slowing down on the read-and-set-up phase.

How do I handle the performance task?

Read the prompt twice before writing anything. The performance task usually has several connected parts — answer each part separately and show ALL work, even when an answer seems obvious. Partial credit on multi-part items adds up.

When do SBAC results come back?

Depends on the state, but most release individual reports in late summer or early fall. California, for example, posts results to families in late August or September.

Related Lessons You May Like

• How to solve multi-step equations
• How to find the slope of a line
• How to graph linear equations
• How to use the Pythagorean Theorem
• How to find the volume of cylinders and spheres

If you want a workbook that walks every Grade 8 standard step by step, Mastering Grade 8 Math pairs perfectly with these questions. For algebra prep, Pre-Algebra for Beginners covers the linear-equation foundation you will lean on.