5.MD.1: Convert Measurement Units
Also written as 5.MD.A.1 and CCSS.MATH.CONTENT.5.MD.A.1 · Cluster: Convert like measurement units within a given measurement system.
The Official Wording
Convert among different-sized standard measurement units within a given measurement system (e.g., convert 5 cm to 0.05 m), and use these conversions in solving multi-step, real world problems.
Common Core State Standards, Grade 5, Measurement & Data · Read it at the source · Checked October 14, 2026
What 5.MD.1 Means in Plain English
Fifth graders change a measurement into a different unit of the same system: 5 cm is 0.05 m, and 3 1/2 feet is 42 inches. Then they use those conversions inside a problem, like whether a 1.5 L bottle fills four 350 mL cups.
In 4th grade the conversions went only from larger to smaller units, like feet to inches (4.MD.1). Now both directions count, and decimals make meters and centimeters feel like place value (5.NBT.2). In 6th grade the same moves become unit rates and ratio tables (6.RP.3).
5.MD.1 I Can Statements
- I can convert within the metric system, like 5 cm to 0.05 m.
- I can convert within customary units, like 3 1/2 feet to inches.
- I can use a conversion to solve a multi-step problem.
5.MD.1 Worked Example
A juice problem where the two amounts cannot be compared until one of them changes units.
A 1.5-liter bottle of juice is poured into four cups that each hold 350 milliliters. Is there enough juice, and how much is left over or missing?
- The bottle is in liters and the cups in milliliters. Convert the bottle to milliliters: 1 L = 1,000 mL, so multiply by 1,000.1.5 L = 1.5 × 1,000 = 1,500 mL
- Find how much the four cups need in total.4 × 350 mL = 1,400 mL
- Compare the two amounts now that they share a unit.1,500 mL > 1,400 mL, so there is enough
- Subtract to find the leftover, and say it in both units.1,500 − 1,400 = 100 mL = 0.1 L
Check it: Reverse the conversion: 1,400 mL is 1.4 L, and 1.5 L − 1.4 L = 0.1 L, the same 100 mL. It makes sense too: four cups of about a third of a liter use a little under 1.5 L.
Common Mistakes with 5.MD.1
Dividing when you should multiply
1.5 L = 1.5 ÷ 1,000 = 0.0015 mL
Try this: Ask which unit is smaller. Milliliters are tiny, so a bottle holds many of them: the number must get bigger, so multiply.
Treating customary units like metric
3 1/2 feet = 35 inches
Try this: Post the non-ten facts, 12 inches in a foot and 16 ounces in a pound, then multiply: 3 1/2 × 12 = 42.
Comparing numbers in different units
“1.5 is less than 1,400, so there is not enough juice”
Try this: Make it a rule: no comparing, adding or subtracting until both measurements wear the same unit. Convert first, then compare.
Where 5.MD.1 Fits
Practice 5.MD.1
Quick Check
- Convert 4.2 kilometers to meters.
- Convert 2 1/4 pounds to ounces.
- A ribbon is 3 m long. You cut off 125 cm. How much ribbon is left, in centimeters?