Generate measurement data by measuring lengths using rulers marked with halves and fourths of an inch. Show the data by making a line plot, where the horizontal scale is marked off in appropriate units - whole numbers, halves, or quarters.
Official wording from the Common Core State Standards for Mathematics (Β© 2010 National Governors Association Center for Best Practices and Council of Chief State School Officers). View on thecorestandards.org
Rulers have lots of small marks, and third graders learn what the half-inch and quarter-inch marks mean. Measuring a crayon might give 3 1/4 inches, which means three whole inches and one more quarter. Students line up the object with the zero mark, read to the nearest quarter inch, and write the length as a whole number, a mixed number or a fraction.
Measurements become data when the whole class measures something, such as the lengths of pencils, leaves or worms in a science lesson. Students then show the data on a line plot: a number line marked in quarter or half inches with an X above each measurement. The plot shows at a glance which lengths are most common and how spread out the data are. Building the scale requires the same fraction understanding as 3.NF.A.2, so this standard is where fractions and measurement meet. Reading questions might ask how many objects were longer than 4 inches or what the most common length was.
Students who line objects up with the 1 on the ruler get answers one inch too long. Show where zero is, especially on rulers with a blank edge.
Children may count tick marks from the start instead of the spaces between them. Highlight that each quarter inch is a space.
The mark halfway between 2 and 3 is 2 1/2, not 2 1/4. Label halves first, then quarters on a paper ruler.
Line plots must have equal spacing for each quarter inch. Skipping values with no data distorts the picture.
Five pencils measure 4 1/4, 4 1/2, 4 1/4, 5 and 4 3/4 inches. Make a line plot and find the most common length.
Answer: The most common length is 4 1/4 inches.
Make paper rulers by folding strips into halves and fourths, then compare them with real rulers. Real measuring tasks, such as measuring hand spans or plant heights, produce authentic data for line plots and make the fractions meaningful.
Tests often show an object next to a ruler, or give a data set to plot and ask a question about the plot. Make sure students can read lengths that end exactly on quarter marks and that they count Xs carefully.
Original questions written for this standard. Choose an option or type your answer, then press Check. Every question has a worked explanation.
Answer: A) 3 1/2 inches
Two quarter inches make one half inch, so the crayon is 3 1/2 inches long.
Answer: 9
Count all the Xs: 3 + 4 + 2 = 9 measurements.
Answer: C) 5 inches
She started at 1, not 0, so the length is 6 - 1 = 5 inches.
Answer: 2 1/2 (also accepted: 2 1/2 inches)
The tallest stack, 4 Xs, is above 2 1/2, so 2 1/2 inches is the most common length.
Answer: A) 1, 1 1/4, 1 1/2, 1 3/4, 2
A quarter-inch scale goes up by 1/4 each time: 1, 1 1/4, 1 1/2, 1 3/4, 2.
Answer: 3
5 - 2 = 3 more leaves are 3 inches long.
Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.
A full lesson with slides, activities and an exit ticket on measuring lengths and making line plots, pitched to grade 3 and editable in PowerPoint or Google Slides.
Make a lesson βA printable, differentiated worksheet on 3.MD.B.4 with an answer key, ready in about a minute.
Make a worksheet βTurn measuring lengths and making line plots into a quiz students answer online that marks itself, with a class summary for you.
Build a test βMeasuring to the nearest half and fourth (quarter) of an inch. Eighths of an inch appear in 4.MD.B.4.
A number line with an X (or dot) above it for every data value. It shows how often each measurement occurs.