What this lesson shows
9 + □ = 12, 17 = □ + 5, and □ − 4 = 8, each turned into a fact you know.
The worked example
The lesson works this one step by step: 9 + □ = 12. Then your kid tries one like it on paper.
The steps
- Say it with "what"
- Find it with a fact you know
- Write it in the box
Helping at home
Say the problem with "what" for the box: "9 plus what makes 12?" Then find it with a fact you know, adding or taking away. The total can come first.
If your kid gets stuck
Say it with "what" for the box.
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 1.OA.D.8
Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = _ - 3, 6 + 6 = _.
Matches standards in 46 statesSee each state's code
- Alabama MA19.1.8
- Alaska 1.OA.8
- Arizona 1.OA.D.8
- Arkansas 1.CAR.9
- California 1.OA.D.8
- Colorado 1.OA.D.8
- Connecticut 1.OA.D.8
- Delaware 1.OA.D.8
- District of Columbia 1.OA.D.8
- Florida MA.1.AR.2.3
- Georgia 1.NR.2.6
- Hawaii 1.OA.D.8
- Idaho 1.OA.D.8
- Illinois 1.OA.D.8
- Iowa 1.OA.D.8
- Kansas 1.OA.8
- Kentucky KY.1.OA.8
- Louisiana 1.OA.D.8
- Maine 1.OA.D.8
- Maryland 1.AT.A.3
- Massachusetts 1.OA.D.8
- Michigan 1.OA.D.8
- Minnesota 1.2.2.3
- Mississippi 1.OA.8
- Missouri 1.RA.A.4
- Montana MT.1.OA.9
- Nebraska 1.N.5.c
- Nevada 1.OA.D.8
- New Hampshire 1.OA.D.8
- New Jersey 1.OA.D.8
- New Mexico 1.OA.D.8
- New York NY-1.OA.8
- North Carolina NC.1.OA.8
- Ohio 1.OA.8
- Oklahoma 3.A.2.1
- Oregon 1.OA.D.8
- Rhode Island 1.OA.D.8
- South Carolina 2.PAFR.1.7, 1.PAFR.1.6
- South Dakota 1.OA.D.8
- Tennessee 1.OA.D.8
- Texas 111.3.b.3.B, 111.3.b.5.F
- Utah 1.OA.8
- Vermont 1.OA.D.8
- Virginia 1.CE.1g, 2.CE.1g
- Washington 1.OA.D.8
- West Virginia M.1.8