The zero in the second row: 4th grade math lesson

What this lesson shows

Fixes a mistake

Multiplying by the tens digit makes tens, so the second row starts with a 0.

The worked example

The lesson works this one step by step: 34 × 26. Then your kid tries one like it on paper.

The steps

The tens digit means tens
Write the 0 first
Check with an estimate

Helping at home

Before the second row, ask what the tens digit really means: 2 tens is 20. Everything that row makes is tens, so write the 0 first. Check the answer against an estimate.

If your kid gets stuck

Write the 0 before you start the second row.

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 4.NBT.B.5
Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
Common Core 5.NBT.B.5
Fluently multiply multi-digit whole numbers using the standard algorithm.

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

Alabama MA19.4.11a, MA19.5.6
Alaska 4.NBT.5, 5.NBT.5
Arizona 4.NBT.B.5 *, 5.NBT.B.5
Arkansas 4.CAR.3, 5.CAR.1
California 4.NBT.B.5, 5.NBT.B.5
Colorado 4.NBT.B.5, 5.NBT.B.5
Connecticut 4.NBT.B.5, 5.NBT.B.5
Delaware 4.NBT.B.5, 5.NBT.B.5
District of Columbia 4.NBT.B.5, 5.NBT.B.5
Florida MA.4.NSO.2.2, MA.4.NSO.2.3, MA.4.NSO.2.5, MA.5.NSO.2.1
Georgia 4.NR.2.3, 5.NR.2.1
Hawaii 4.NBT.B.5, 5.NBT.B.5
Idaho 4.NBT.B.5.a, 4.NBT.B.5.b, 5.NBT.B.5
Illinois 4.NBT.B.5, 5.NBT.B.5
Indiana 4.CA.1
Iowa 4.NBT.B.5, 5.NBT.B.5
Kansas 4.NBT.5, 5.NBT.5
Kentucky KY.4.NBT.5, KY.5.NBT.5
Louisiana 4.NBT.B.5, 5.NBT.B.5
Maine 4.NBT.B.5, 5.NBT.B.5
Maryland 4.NOS.B.4, 4.NOS.B.5.a, 4.NOS.B.5.b, 4.NOS.B.5.c, 4.NOS.B.5.d, 4.NOS.B.6.a, 5.NOS.B.4.a, 5.NOS.B.5.a, 5.NOS.B.4.b, 5.NOS.B.4.c, 5.NOS.B.4.d
Massachusetts 4.NBT.B.5, 5.NBT.B.5
Michigan 4.NBT.B.5, 5.NBT.B.5
Minnesota 3.1.2.5, 4.1.1.3, 4.1.1.4, 5.1.1.3
Mississippi 4.NBT.5, 5.NBT.5
Missouri 4.NBT.A.6, 5.NBT.A.7
Montana MT.4.NBT.5, 4.D1.21, 4.D2.4, 4.D2.9, MT.5.NBT.5, 5.D4.1
Nebraska 4.A.1.b, 4.A.1.d, 5.A.1.a
Nevada 4.NBT.B.5, 5.NBT.B.5
New Hampshire 4.NBT.B.5, 5.NBT.B.5
New Jersey 4.NBT.B.5, 5.NBT.B.5
New Mexico 4.NBT.B.5, 5.NBT.B.5
New York NY-4.NBT.5, NY-5.NBT.5
North Carolina NC.4.NBT.5, NC.5.NBT.5
North Dakota 4.NO.NBT.5, 5.NO.NBT.4
Ohio 4.NBT.5, 5.NBT.5
Oklahoma 3.N.2.8, 4.N.2.2, 4.N.2.3, 5.N.2.1
Oregon 4.NBT.B.5, 5.NBT.B.5
Pennsylvania CC.2.1.4.B.2, CC.2.1.5.B.2
Rhode Island 4.NBT.B.5, 5.NBT.B.5
South Carolina 4.NR.1.2, 5.PAFR.1.1, 4.PAFR.1.3
South Dakota 4.NBT.B.5, 5.NBT.B.5
Tennessee 4.NBT.B.5, 5.NBT.B.5
Texas 111.5.b.4.G, 111.6.b.4.B, 111.6.b.4.C, 111.6.b.4.D, 111.6.b.4.G, 111.7.b.3.B
Utah 4.NBT.5, 5.NBT.5
Vermont 4.NBT.B.5, 5.NBT.B.5
Virginia 4.CE.2a, 4.CE.2g.i, 4.CE.2g.ii, 4.CE.2g.iii, 5.CE.1a, 5.CE.1b.i, 5.CE.1b.ii, 5.CE.1b.iii, 5.CE.1b.iv
Washington 4.NBT.B.5, 5.NBT.B.5
West Virginia M.4.10, M.5.8
Wisconsin M.4.NBT.B.5, M.4.NBT.A.3, M.5.NBT.B.5
Wyoming 4.NBT.5a, 4.NBT.5b, 4.NBT.5c, 4.NBTP.5.A, 4.NBTP.5.B, 4.NBTP.5.C

The zero in the second row