IQR: Sort, Split and Find the Middle Half

Interquartile Range Practice for Grade 6: Sort, Split and Find Q1, Q3 and the IQR

Finding the interquartile range is a sequence of small steps, and most students who get it wrong slip on one of them. They skip putting the data in order, they forget to leave the median out when the count is odd, or they pick the wrong value for Q1 or Q3. This interactive worksheet makes students do each step themselves and checks them as they go, so you can see where the method breaks down instead of only seeing a wrong final answer.

Each question uses a real-world data set, such as puzzle times, pets per home, screen time or points scored. Students:

• Put the data in order. They type the values from smallest to largest, and the worksheet checks the order before they can continue.
• Split the data into halves. A “Show halves” step draws the dividing line for an even count, or fades out the median for an odd count, so students see which values belong to each half.
• Find Q1, Q3 and the IQR. Students work out the median of each half and subtract. Feedback names the specific error, such as “Q3 is right. Q1 should sit in the middle of the lower half.”
• See the middle half. A correct answer brings up a number line with Q1 and Q3 marked and the middle 50% of the data shaded.
• Compare spread. The last two questions give students two data sets side by side. They find both IQRs and decide which set is more consistent, which connects the number to what it means.

What’s included

• 8 questions: 6 full sort, split and solve problems, plus 2 questions comparing variability
• Odd and even data sets, so students practice both ways of splitting
• Randomized data for every student, which cuts down on copying and makes the worksheet reusable for retakes
• Automatic grading, with scores sent to your teacher dashboard
• A reference strip at the top with the definitions of Q1, Q3 and IQR
• No calculator needed; takes 20 to 30 minutes

Standards alignment

• 6.SP.B.5c: Give quantitative measures of variability (interquartile range) for a data set
• 6.SP.A.3: Recognize that a measure of variation describes how the values vary with a single number
• Also works as review before 7.SP.B.3, comparing the variability of two data distributions

Good for

• Introducing or practicing interquartile range after a lesson on median
• Small-group intervention, since the step-by-step feedback acts as a built-in hint
• A quick check before teaching box plots, which build directly on Q1, Q3 and the median
• Homework or sub plans that grade themselves

Keywords: interquartile range worksheet, IQR practice, finding quartiles, Q1 and Q3, measures of variability, grade 6 statistics, 6.SP.B.5c, middle school data analysis, digital math worksheet, self-grading math activity