Unit 2 MSTAR-Style Practice Test · Form B

Understanding the World Around Us Through Statistics · 12 questions · English only, like the real test · No timer — take the time you need.

These are MSTAR-style questions written for this curriculum to rehearse the format. They are not official Maryland assessment items. MSTAR — Maryland's new state test, first given in spring 2027 — uses the same kinds of questions you see here: selected response, select-all, two-part evidence questions, and written responses.

How this works: Answer every question, then press Submit & Grade. Selected-response parts grade instantly with an explanation for each; written responses go to your teacher. Your answers save on this device.

On the real MSTAR: math runs as three 40-minute sessions, in English, on a computer. Here there is no clock — practice the thinking first; the pacing comes with rehearsal.

Written responses: how should the explain-the-error questions be scored?

Instant scoring checks whether your explanation states the value and uses the reasoning the question is about. It matches words and numbers, so a right answer worded differently can score low — your teacher can always re-score it from the answer key.

16.DS.1Understand Statistical Questions

Part A

Which question is a STATISTICAL question?

How many minutes did I sleep last night? How many students are in our class? What time does school start? How many minutes did each student in our class sleep last night?

Part B

What makes the other three questions non-statistical?

They are about school instead of about students. They use smaller numbers. Each has a single fixed answer, so there is no variability to describe. They cannot be answered with data.

26.DS.5Represent and Describe Data in a Histogram

Select all that apply

Select ALL statements that are true about histograms:

The intervals must be equal in width. The height of each bar is the frequency of values in that interval. Bars touch because the intervals are continuous. You can read every individual data value directly off a histogram. Intervals must not overlap.

36.DS.4Describe the Data Using the Median

Part A

Find the median of this data set: 12, 7, 15, 9, 20, 11, 8.

9 11 12 15

Part B

Why must the data be put in order before finding the median?

Ordering makes the numbers easier to add. The median is always the largest value. The median is the middle value by position in the ordered list, not by where it was written. Ordering changes the median to a whole number.

46.DS.5Represent and Describe Data in a Box Plot

Part A

A box plot has a 5-number summary of minimum 4, Q1 = 8, median 12, Q3 = 18, maximum 24. What is the interquartile range?

6 10 12 20

Part B

What does the box itself represent in a box plot?

All of the data from minimum to maximum. The mean of the data set. The middle 50% of the data, from Q1 to Q3. The values that occur most often.

56.DS.3Describe Data by Range and Interquartile Range

Explain the error

Lena compared two data sets. Both had a median of 50. She concluded: 'The two sets are the same because their medians match.'

Explain why Lena's conclusion may be wrong, and name a measure that would tell the sets apart.

✍️ Written response — 2 points.

66.NOS.2Divide Multi-Digit Numbers Using an Algorithm

Part A

Use the long division algorithm to find 936 ÷ 4.

209 232 234 243

Part B

In the D-M-S-B cycle, what does the SUBTRACT step tell you?

How many times the divisor fits into the whole dividend. How much of the current value is left over before the next digit is brought down. Whether the quotient will be even. The final remainder of the entire problem.

76.NOS.3Divide Decimals Using an Algorithm

Explain the error

Bianca computed 7.5 ÷ 0.5. She slid the divisor's point to make it 5, but left the dividend as 7.5, and wrote '7.5 ÷ 5 = 1.5.'

Explain Bianca's misconception and give the correct quotient.

✍️ Written response — 2 points.

86.DS.4Describe Data Using the Mean

Select all that apply

Select ALL statements that are true about the mean:

Mean = sum of all values ÷ number of values. Adding one very large value pulls the mean upward. The mean must be one of the values in the data set. The mean can be a decimal even when every value is a whole number. The mean uses every value in the data set.

96.DS.6cDescribe Data by Mean Absolute Deviation

Part A

A data set is 3, 5, 9, 11 with a mean of 7. What is the mean absolute deviation?

2 3 7 28

Part B

Why are the DISTANCES from the mean used rather than the signed differences?

Distances are easier to add. Negative numbers cannot be divided. The signed differences always add to zero, so they would give a MAD of 0 for every data set. The mean is always larger than every value.

106.DS.6dChoose Appropriate Measures

Part A

A data set of house prices contains one mansion worth far more than every other home. Which pair of measures best describes this data?

Median and IQR Mean and MAD Mean and range Mode and range

Part B

When are the mean and MAD the better choice?

Whenever the data set is large. Whenever the values are whole numbers. Only when the median cannot be found. When the data is roughly symmetric with no outliers.

116.NOS.3Add and Subtract Decimals

Explain the error

Malik computed 9.6 + 0.45 by lining up the RIGHT-hand edges of the digits, as if adding whole numbers. He got 1.41.

Explain Malik's misconception and give the correct sum.

✍️ Written response — 2 points.

126.NOS.3Multiply Decimals

Select all that apply

Select ALL statements that are true about multiplying decimals:

Multiply the factors as if they were whole numbers first. The total number of decimal places in the factors gives the number in the product. Multiplying by a number less than 1 gives a product smaller than the other factor. The decimal points must be lined up before multiplying. Estimating first is a good way to check the placement of the decimal point.

Unit 2 MSTAR-Style Practice Test — Form B