What this lesson shows
Fixes a mistake
In the bird story, 12 is the total. The answer is 7, not 12 + 5.
The worked example
The lesson works this one step by step: some stars, get 5 more, now 12. Then your kid tries one like it on paper.
The steps
- Find the total
- The rest are parts
- Total minus a part
- Check by adding
Helping at home
Find the total first: the number you have now. The other numbers are parts. To find a missing part, take the known part from the total, then check by adding.
If your kid gets stuck
Which number is the total?
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 2.OA.A.1
Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
Matches standards in 50 statesSee each state's code
- Alabama MA19.2.1
- Alaska 2.OA.1
- Arizona 2.OA.A.1
- Arkansas 2.CAR.7
- California 2.OA.A.1
- Colorado 2.OA.A.1
- Connecticut 2.OA.A.1
- Delaware 2.OA.A.1
- District of Columbia 2.OA.A.1
- Florida MA.2.AR.1.1
- Hawaii 2.OA.A.1
- Idaho 2.OA.A.1
- Illinois 2.OA.A.1
- Indiana 2.CA.1
- Iowa 2.OA.A.1
- Kansas 2.OA.1
- Kentucky KY.2.OA.1
- Louisiana 2.OA.A.1
- Maine 2.OA.A.1
- Maryland 2.AT.A.1, 2.AT.A.2
- Massachusetts 2.OA.A.1
- Michigan 2.OA.A.1
- Minnesota 2.1.2.5, 2.2.2.1, 2.2.2.2
- Mississippi 2.OA.1
- Missouri 2.NBT.C.11
- Montana MT.2.OA.1
- Nebraska 2.N.5.a, 2.N.5.b
- Nevada 2.OA.A.1
- New Hampshire 2.OA.A.1
- New Jersey 2.OA.A.1
- New Mexico 2.OA.A.1
- New York NY-2.OA.1.a, NY-2.OA.1.b
- North Carolina NC.2.OA.1.a.1, NC.2.OA.1.b.1, NC.2.OA.1.b.2
- North Dakota 2.AR.OA.3, 2.AR.OA.4
- Ohio 2.OA.1
- Oklahoma 2.N.2.5, 2.A.2.2
- Oregon 2.OA.A.1
- Pennsylvania CC.2.2.2.A.1
- Rhode Island 2.OA.A.1
- South Carolina 2.PAFR.1.3
- South Dakota 2.OA.A.1
- Tennessee 2.OA.A.1
- Texas 111.4.b.4.C, 111.4.b.4.D, 111.4.b.7.C
- Utah 2.OA.1
- Vermont 2.OA.A.1
- Virginia 2.CE.1c
- Washington 2.OA.A.1
- West Virginia M.2.1
- Wisconsin M.2.OA.A.1
- Wyoming 2.OA.1