Trade only when you need to: 2nd grade math lesson

What this lesson shows

Fixes a mistake

325 + 37: 12 ones need a trade, but 6 tens do not. The sum is 362.

The worked example

The lesson works this one step by step: 325 + 37. Then your kid tries one like it on paper.

The steps

Add the ones
Trade 10 or more
Fewer than 10 stays
Add each place

Helping at home

Add one place at a time. Trade only when a place makes 10 or more: 10 ones for a ten, or 10 tens for a hundred. Fewer than 10 stays.

If your kid gets stuck

Is it 10 or more?

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 2.NBT.B.7
Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.

Matches standards in 45 statesSee each state's code

Alabama MA19.2.12a
Alaska 2.NBT.7
Arizona 2.NBT.B.7
Arkansas 2.CAR.6
California 2.NBT.B.7
Colorado 2.NBT.B.7
Connecticut 2.NBT.B.7
Delaware 2.NBT.B.7
District of Columbia 2.NBT.B.7
Florida MA.2.NSO.2.4
Hawaii 2.NBT.B.7
Idaho 2.NBT.B.7.a, 2.NBT.B.7.b
Illinois 2.NBT.B.7
Indiana 2.CA.2
Iowa 2.NBT.B.7
Kansas 2.NBT.7
Kentucky KY.2.NBT.7.a, KY.2.NBT.7.b
Louisiana 2.NBT.B.7
Maine 2.NBT.B.7
Maryland 2.NOS.C.9.a, 2.NOS.C.9.b, 2.NOS.C.9.c, 2.NOS.C.9.d
Massachusetts 2.NBT.B.7
Michigan 2.NBT.B.7
Mississippi 2.NBT.7
Missouri 2.NBT.B.8
Montana MT.2.NBT.7
Nebraska 2.N.4.e
Nevada 2.NBT.B.7
New Hampshire 2.NBT.B.7
New Jersey 2.NBT.B.7
New Mexico 2.NBT.B.7
New York NY-2.NBT.7.a, NY-2.NBT.7.b
North Carolina NC.2.NBT.7.a, NC.2.NBT.7.b, NC.2.NBT.7.c, NC.2.NBT.7.d
Ohio 2.NBT.7
Oregon 2.NBT.B.7
Pennsylvania CC.2.1.2.B.3
Rhode Island 2.NBT.B.7
South Dakota 2.NBT.B.7
Tennessee 2.NBT.C.7
Texas 111.4.b.4.C, 111.4.b.4.D
Utah 2.NBT.7
Vermont 2.NBT.B.7
Washington 2.NBT.B.7
West Virginia M.2.12
Wisconsin M.2.NBT.B.7
Wyoming 2.NBT.7a, 2.NBT.7b, 2.NBT.7c, 2.NBTP.7.A, 2.NBTP.7.B, 2.NBTP.7.C

Trade only when you need to