Wisconsin Grade 4 Math

A blank position is not a zero-length ribbon

Six ribbons were measured in inches. The line plot shows one X for each ribbon: two at 1/2 inch, one at 3/4 inch, none at 1 inch, one at 1 1/4 inches, and two at 1 1/2 inches. Find the difference between the longest and shortest ribbons. Explain what the empty 1-inch position means.

Follow the reasoning

The shortest recorded measurement is 1/2 inch and the longest is 1 1/2 inches. Their difference is 1 1/2 − 1/2 = 1 inch. In quarter-inch units, this is 6/4 − 2/4 = 4/4. The X marks total 2 + 1 + 0 + 1 + 2 = 6 ribbons. The blank above 1 inch means that none of these six ribbons has that measurement. It does not add a ribbon of length zero, and it does not mean the neighboring measurements are missing. The horizontal positions represent lengths; the number of X marks represents how many ribbons have each length. Keeping those two quantities separate prevents subtracting frequencies when the question asks for a difference in lengths.

Check the explanation

These are invented exact classroom measurements. The line plot describes this set of six ribbons; it is not a claim about all ribbons or an actual school collection. No mark at a length means a frequency of zero at that length, rather than an observation of length zero.

Try the next step

Add one ribbon measuring 1 3/4 inches. The set now has seven ribbons, and the longest-shortest difference becomes 1 3/4 − 1/2 = 1 1/4 inches. Explain why adding another ribbon at 3/4 inch would change the count but leave the original range unchanged.

Wisconsin reference for this worked activity

The Wisconsin mathematics standards page links the state’s 2021 standards, formally adopted May 10, 2021. State standards serve as a model, and local school boards select standards and curriculum for their communities. The document connects mathematical practices and content; develop both in classroom work. Read the complete requirements and the school’s current curriculum sequence. The reference below selects one worked focus.

This selected reference identifies the activity focus. The complete standard and grade curriculum include additional work. These labels do not certify alignment of every independent lesson, worksheet, or quiz in the broader directory.

Choose a next task from the student’s explanation

Use a different set of numbers to check whether the student can explain the same relationship. If the explanation is unclear, return to the model; if the reasoning is sound but a calculation is wrong, work through a shorter calculation and check it against the model. Use the related learning resources alongside the teacher’s assigned goals.

Wisconsin DPI’s Forward Exam overview lists English language arts and mathematics in Grades 3–8, science in Grades 4 and 8, and social studies in Grades 4, 8, and 10. Grade 4 is included in that mathematics range. Follow current school directions and accommodations. Independently published practice has its own tools, timing, questions, and scoring; its result does not establish a state performance level. This original worked activity is not an official assessment item. Read Wisconsin assessment guidance.

State sources and the selected complete PDF page checked October 6, 2026. Confirm later guidance and local assignments before planning assessment preparation.