Subtracting across zeros: 3rd grade math lesson

What this lesson shows

Fixes a mistake

8,000 − 1,432: the zeros trade down one place at a time.

The worked example

The lesson works this one step by step: 8,000 − 1,432. Then your kid tries one like it on paper.

The steps

Never turn a column around
Go left past the zeros
Each 0 keeps 9
Check by adding back

Helping at home

When the top digit is 0 and the places to its left are 0 too, go left to the first place that has something. Trade down one place at a time: each 0 takes 10 and lends 1, keeping 9. Never turn a column around.

If your kid gets stuck

Go left to the first place that has something.

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 3.NBT.A.2
Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.
Common Core 4.NBT.B.4
Fluently add and subtract multi-digit whole numbers using the standard algorithm.

Matches a standard in all 50 states and DCSee each state's code

Alabama MA19.3.11, MA19.4.10
Alaska 3.NBT.2, 4.NBT.4
Arizona 3.NBT.A.2 *, 4.NBT.B.4
Arkansas 3.CAR.1, 4.CAR.2
California 3.NBT.A.2, 4.NBT.B.4
Colorado 3.NBT.A.2, 4.NBT.B.4
Connecticut 3.NBT.A.2, 4.NBT.B.4
Delaware 3.NBT.A.2, 4.NBT.B.4
District of Columbia 3.NBT.A.2, 4.NBT.B.4
Florida MA.3.NSO.2.1
Georgia 3.PAR.2.1, 3.PAR.2.2, 4.NR.2.1
Hawaii 3.NBT.A.2, 4.NBT.B.4
Idaho 3.NBT.A.2, 4.NBT.B.4
Illinois 3.NBT.A.2, 4.NBT.B.4
Indiana 3.CA.2, 3.CA.1
Iowa 3.NBT.A.2, 4.NBT.B.4
Kansas 3.NBT.2, 4.NBT.4
Kentucky KY.3.NBT.2, KY.4.NBT.4
Louisiana 3.NBT.A.2, 4.NBT.B.4
Maine 3.NBT.A.2, 4.NBT.B.4
Maryland 3.NOS.D.7.a, 3.NOS.D.7.b, 3.NOS.D.7.c, 4.NOS.B.3.b, 4.NOS.B.3.c, 4.NOS.B.3.d
Massachusetts 3.NBT.A.2, 4.NBT.B.4
Michigan 3.NBT.A.2, 4.NBT.B.4
Minnesota 3.1.2.1, 3.1.2.2
Mississippi 3.NBT.2, 4.NBT.4
Missouri 3.NBT.A.3, 4.NBT.A.5, 5.NBT.A.6
Montana MT.3.NBT.2, MT.4.NBT.4, 4.D1.5, 4.D2.7
Nebraska 3.A.1.a, 4.A.1.a
Nevada 3.NBT.A.2, 4.NBT.B.4
New Hampshire 3.NBT.A.2, 4.NBT.B.4
New Jersey 3.NBT.A.2, 4.NBT.B.4
New Mexico 3.NBT.A.2, 4.NBT.B.4
New York NY-3.NBT.2, NY-4.NBT.4
North Carolina NC.3.NBT.2.a, NC.3.NBT.2.b, NC.3.NBT.2.c, NC.4.NBT.4
North Dakota 3.NO.NBT.3, 4.NO.NBT.4
Ohio 3.NBT.2, 4.NBT.4
Oklahoma 3.N.2.3
Oregon 3.NBT.A.2, 4.NBT.B.4
Pennsylvania CC.2.1.3.B.1, CC.2.1.4.B.2
Rhode Island 3.NBT.A.2, 4.NBT.B.4
South Carolina 3.PAFR.1.1, 4.PAFR.1.1, 3.PAFR.2.2
South Dakota 3.NBT.A.2, 4.NBT.B.4
Tennessee 3.NBT.A.2, 4.NBT.B.4
Texas 111.5.b.4.A, 111.5.b.5.A, 111.6.b.4.A
Utah 3.NBT.2, 4.NBT.4
Vermont 3.NBT.A.2, 4.NBT.B.4
Virginia 3.CE.1c, 3.CE.1e, 4.CE.1c, 4.CE.1d
Washington 3.NBT.A.2, 4.NBT.B.4
West Virginia M.3.13, M.4.9
Wisconsin M.4.NBT.B.4, M.3.NBT.A.2
Wyoming 3.NBT.2

Subtracting across zeros