Same-size wholes: 5th grade math lesson

What this lesson shows

Fixes a mistake

Thirds of a circle and fourths of a rectangle cannot be added. One whole, one shape.

The worked example

The lesson works this one step by step: 2/3 + 1/4. Then your kid tries one like it on paper.

The steps

Different wholes can’t be added
Same-size bars
Cut, rename, add the tops

Helping at home

Draw every fraction on the same whole: bars of the same shape and size. Cut both bars until the parts match, rename, then add the tops.

If your kid gets stuck

One whole, one shape. Same-size bars, then rename.

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.

See how Lux works

Standards

Common Core 5.NF.A.1
Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12. (In general, a/b + c/d = (ad + bc)/bd.)

Matches standards in 49 statesSee each state's code

Alabama MA19.5.10
Alaska 5.NF.1
Arizona 5.NF.A.1
Arkansas 5.CAR.5
California 5.NF.A.1
Colorado 5.NF.A.1
Connecticut 5.NF.A.1
Delaware 5.NF.A.1
District of Columbia 5.NF.A.1
Florida MA.5.FR.2.1
Georgia 5.NR.3.3
Hawaii 5.NF.A.1
Idaho 5.NF.A.1
Illinois 5.NF.A.1
Indiana 5.CA.3
Iowa 5.NF.A.1
Kansas 5.NF.1
Kentucky KY.5.NF.1
Louisiana 5.NF.A.1
Maine 5.NF.A.1
Maryland 5.NOS.C.8.b, 5.NOS.C.8.c
Massachusetts 5.NF.A.1
Michigan 5.NF.A.1
Minnesota 5.1.3.1, 5.1.3.2
Mississippi 5.NF.1
Missouri 5.NF.B.6
Montana MT.5.NF.1, 5.D2.5, 5.D3.4
Nebraska 5.N.3.e
Nevada 5.NF.A.1
New Hampshire 5.NF.A.1
New Jersey 5.NF.A.1
New Mexico 5.NF.A.1
New York NY-5.NF.1
North Dakota 5.NO.NF.3
Ohio 5.NF.1
Oklahoma 5.N.3.3
Oregon 5.NF.A.1
Pennsylvania CC.2.1.5.C.1
Rhode Island 5.NF.A.1
South Carolina 5.PAFR.2.1, 5.PAFR.3.1
South Dakota 5.NF.A.1
Tennessee 5.NF.A.1
Texas 111.7.b.3.H, 111.7.b.3.K
Utah 5.NF.1
Vermont 5.NF.A.1
Virginia 5.CE.2a, 5.CE.2b
Washington 5.NF.A.1
West Virginia M.5.11
Wisconsin M.5.NF.A.1

Same-size wholes