4.MD.1: Relative Sizes of Measurement Units
Also written as 4.MD.A.1 and CCSS.MATH.CONTENT.4.MD.A.1 · Cluster: Solve problems involving measurement and conversion of measurements.
The Official Wording
Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two-column table. For example, know that 1 ft is 12 times as long as 1 in. Express the length of a 4 ft snake as 48 in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), ...
Common Core State Standards, Grade 4, Measurement & Data · Read it at the source · Checked October 14, 2026
What 4.MD.1 Means in Plain English
Fourth graders learn how many times bigger one unit is than another: a kilometer is 1,000 meters, a pound is 16 ounces, an hour is 60 minutes. Then they convert a larger unit into a smaller one, like 3 kg = 3,000 g, and build a two-column table.
Each conversion is a times-as-many comparison (4.OA.1): a pound is 16 times as heavy as an ounce, so 5 pounds is 5 × 16 = 80 ounces. In 5th grade conversions run both ways and include decimals, like 250 cm = 2.5 m (5.MD.1).
4.MD.1 I Can Statements
- I can say how many times bigger one unit is than another.
- I can convert a larger unit to a smaller one, like hours to minutes.
- I can make a two-column conversion table and use its pattern.
4.MD.1 Worked Example
A puppy on a vet’s scale that reads only in ounces, solved with the two-column table the standard asks for.
Mia’s puppy weighs 7 pounds. The vet’s scale reads in ounces. Make a pounds-to-ounces table and find the puppy’s weight in ounces.
- Start with the fact that sets up the table: one pound is 16 times as heavy as one ounce.1 lb = 16 oz
- Each extra pound adds another 16 ounces, so every row is the pounds times 16.(1, 16), (2, 32), (3, 48), (4, 64)
- Keep the pattern going to 7 pounds, or jump straight there by multiplying in parts.7 × 16 = 7 × 10 + 7 × 6 = 70 + 42 = 112
- Write the answer in the unit the scale uses.7 lb = 112 oz
Check it: Use the table: 4 lb is 64 oz and 3 lb is 48 oz, and 64 + 48 = 112 ounces. The smaller unit gives the bigger number, as it should.
Common Mistakes with 4.MD.1
Getting fewer of the smaller unit
5 pounds = 5 ÷ 16 ounces, “because ounces are smaller”
Try this: Measure a desk in meters, then in centimeters: the small unit takes many more. Smaller units always mean a bigger count.
Using 100 for every conversion
2 hours = 200 minutes
Try this: Post the key facts where students can see them: 60 minutes in an hour, 16 ounces in a pound, 1,000 grams in a kilogram.
Gluing mixed units together
2 lb 5 oz = 25 oz
Try this: Convert only the pounds, then add the leftover ounces: 2 lb = 32 oz, and 32 + 5 = 37 oz.
Where 4.MD.1 Fits
Practice 4.MD.1
Quick Check
- How many grams are in 4 kilograms?
- Complete the hours-to-minutes table: (1, 60), (2, ?), (3, ?)
- A movie lasts 2 hours 15 minutes. How many minutes is that?