What this lesson shows
Fixes a mistake
3 feet − 6 inches is 2 feet 6 inches, not 2 feet 4 inches. A foot is 12 inches.
The worked example
The lesson works this one step by step: 3 feet − 6 inches. Then your kid tries one like it on paper.
The steps
- Not by ten
- Regroup by the unit
- Then subtract
Helping at home
When you subtract measures and need more of the small unit, regroup 1 big unit by its own size: 1 foot is 12 inches, 1 hour is 60 minutes, 1 pound is 16 ounces, 1 gallon is 4 quarts. Never by 10.
If your kid gets stuck
How many small units make one big one?
Watch it with Lux
With Lux, this lesson is a narrated video and a printed page your kid works on. Then Lux helps with the same math on their own worksheet, one question at a time.
Standards
- Common Core 5.MD.A.1
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.
Matches standards in 49 statesSee each state's code
- Alabama MA19.5.17
- Alaska 5.MD.1
- Arizona 5.MD.A.1
- Arkansas 5.GM.6
- California 5.MD.A.1
- Colorado 5.MD.A.1
- Connecticut 5.MD.A.1
- Delaware 5.MD.A.1
- District of Columbia 5.MD.A.1
- Florida MA.5.M.1.1
- Georgia 5.MDR.7.1, 5.MDR.7.3, 5.MDR.7.4
- Hawaii 5.MD.A.1
- Idaho 5.MD.A.1
- Illinois 5.MD.A.1
- Indiana 5.M.1
- Iowa 5.MD.A.1
- Kansas 5.MD.1
- Kentucky KY.5.MD.1
- Louisiana 5.MD.A.1
- Maine 5.MD.A.1
- Maryland 5.GR.A.1
- Massachusetts 5.MD.A.1
- Michigan 5.MD.A.1
- Mississippi 5.MD.1
- Missouri 5.GM.D.8, 5.GM.D.9
- Montana MT.5.MD.1, 5.D1.3, 5.D1.10, 5.D2.4
- Nebraska 5.G.3.a
- Nevada 5.MD.A.1
- New Hampshire 5.MD.A.1
- New Jersey 5.M.A.1
- New Mexico 5.MD.A.1
- New York NY-5.MD.1
- North Carolina NC.5.MD.1
- North Dakota 5.GM.M.1
- Ohio 5.MD.1
- Oklahoma 5.GM.3.3, 5.GM.3.4
- Oregon 5.GM.C.4
- Pennsylvania CC.2.4.5.A.1
- Rhode Island 5.MD.A.1
- South Carolina 5.MGSR.2.1
- South Dakota 5.MD.A.1
- Tennessee 5.MD.A.1
- Texas 111.7.b.7
- Utah 5.MD.1
- Vermont 5.MD.A.1
- Virginia 5.MG.1c.i, 5.MG.1c.ii, 5.MG.1c.iii
- Washington 5.MD.A.1
- West Virginia M.5.18
- Wisconsin M.5.MD.A.1