CCSS.Math.Content.2.MD.A.4
The Standard
Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit.
Common Core State Standards for Mathematics · Measurement and Data
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students measure two objects using the same standard unit, such as centimeters or inches. They find the difference between the measurements and state the answer with the correct unit.
What Mastery Looks Like
- A student lines up each object at zero, measures both with the same unit, and records accurate lengths. The student subtracts the shorter length from the longer length and labels the answer correctly.
Common Misconceptions
- Students may compare the two measurements but report the longer length instead of the difference. They may start measuring at the ruler’s edge instead of zero, mix units, or subtract in the wrong order.
How to Assess It
- Give each student two paper strips and a centimeter ruler. Ask them to measure both strips, find how much longer one is, and write an equation with the unit.
Lesson moves
Ways to Teach It
Students measure two pencils with centimeter cubes, line up the cubes, and count the extra cubes beside the longer pencil.
Ask students to explain why 14 centimeters and 9 centimeters have a difference of 5 centimeters using words, numbers, or a drawing.
Partners draw two length cards, subtract the smaller measurement from the larger, and keep the cards when the answer and unit are correct.
Students measure two gift ribbons and calculate how much ribbon must be trimmed so both pieces are the same length.
Free download
Printable 2.MD.A.4 Worksheet
A ready-to-print activity worksheet aligned to CCSS.Math.Content.2.MD.A.4, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetLearning progression
Where This Standard Sits
See the whole path on the Measurement & Data progression map.
Before This Standard
If students are struggling here, check these first.
- CCSS.Math.Content.1.MD.A.2
Comparing how much longer requires understanding length as equal units laid end to end, then subtracting or counting the extra units.
- CCSS.Math.Content.2.MD.A.1
Students must use rulers or other length tools accurately before they can measure two objects and state the difference in standard units.
- CCSS.Math.Content.1.OA.A.1
Comparing lengths uses the same take-apart or comparison thinking to find the difference between two measured amounts.
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