What this lesson shows
Fixes a mistake
A 60 degree angle read as 120: check against "is it less than a right angle?"
The worked example
The lesson works this one step by step: 60°. Then your kid tries one like it on paper.
The steps
- Two numbers at the ray
- Is it less than 90°?
- Rule one out
- Read the row from 0
Helping at home
Where the ray crosses, a protractor shows two numbers that add to 180. Ask first: is the angle smaller than a right angle, or wider? That rules one out. Then read the row that starts at 0 on the bottom ray.
If your kid gets stuck
Smaller than a right angle means less than 90°.
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 4.MD.C.6
Measure angles in whole-number degrees using a protractor. Sketch angles of specified measure.
Matches standards in 46 statesSee each state's code
- Alabama MA19.4.25
- Alaska 4.MD.8
- Arizona 4.MD.C.6
- Arkansas 4.GM.2
- California 4.MD.C.6
- Colorado 4.MD.C.6
- Connecticut 4.MD.C.6
- Delaware 4.MD.C.6
- District of Columbia 4.MD.C.6
- Florida MA.4.GR.1.2
- Hawaii 4.MD.C.6
- Idaho 4.MD.C.6
- Illinois 4.MD.C.6
- Iowa 4.MD.C.6
- Kentucky KY.4.MD.6
- Louisiana 4.MD.C.6
- Maine 4.MD.C.6
- Maryland 4.GR.B.6
- Massachusetts 4.MD.C.6
- Michigan 4.MD.C.6
- Minnesota 4.3.2.1
- Mississippi 4.MD.6
- Missouri 4.GM.B.4, 4.GM.B.5
- Montana MT.4.MD.6, 4.D2.1
- Nebraska 4.G.2.b, 4.G.2.d
- Nevada 4.MD.C.6
- New Hampshire 4.MD.C.6
- New Jersey 4.M.B.5
- New Mexico 4.MD.C.6
- New York NY-4.MD.6
- North Carolina NC.4.MD.6.b
- North Dakota 4.GM.M.6
- Ohio 4.MD.6
- Oklahoma 4.GM.2.1, 5.GM.3.1
- Oregon 4.GM.C.8
- Pennsylvania CC.2.4.4.A.6
- Rhode Island 4.MD.C.6
- South Dakota 4.MD.C.6
- Tennessee 4.MD.C.6
- Texas 111.6.b.7.C, 111.6.b.7.D
- Utah 4.MD.6
- Vermont 4.MD.C.6
- Virginia 5.MG.3e, 5.MG.3f
- Washington 4.MD.C.6
- West Virginia M.4.24
- Wisconsin M.4.MD.C.6