What this lesson shows
Fixes a mistake
A second row with a carry never added: 26,680 is far from its estimate, 36,000. Estimate each row before adding.
The worked example
The lesson works this one step by step: 1,834 × 23. Then your kid tries one like it on paper.
The steps
- Estimate each row
- Find the row that is far off
- Fix it, then add
Helping at home
Before adding the rows, estimate each one: the ones digit times the top number rounded to the nearest hundred, then the tens. A row far from its estimate has a slip; look for a carry never added.
If your kid gets stuck
Estimate each row before you add them.
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 5.NBT.B.5
Fluently multiply multi-digit whole numbers using the standard algorithm.
Matches standards in 48 statesSee each state's code
- Alabama MA19.5.6
- Alaska 5.NBT.5
- Arizona 5.NBT.B.5
- Arkansas 5.CAR.1
- California 5.NBT.B.5
- Colorado 5.NBT.B.5
- Connecticut 5.NBT.B.5
- Delaware 5.NBT.B.5
- District of Columbia 5.NBT.B.5
- Florida MA.5.NSO.2.1
- Georgia 5.NR.2.1
- Hawaii 5.NBT.B.5
- Idaho 5.NBT.B.5
- Illinois 5.NBT.B.5
- Iowa 5.NBT.B.5
- Kansas 5.NBT.5
- Kentucky KY.5.NBT.5
- Louisiana 5.NBT.B.5
- Maine 5.NBT.B.5
- Maryland 5.NOS.B.4.b, 5.NOS.B.4.c, 5.NOS.B.4.d
- Massachusetts 5.NBT.B.5
- Michigan 5.NBT.B.5
- Minnesota 4.1.1.3
- Mississippi 5.NBT.5
- Missouri 5.NBT.A.7
- Montana MT.5.NBT.5, 5.D4.1
- Nebraska 5.A.1.a
- Nevada 5.NBT.B.5
- New Hampshire 5.NBT.B.5
- New Jersey 5.NBT.B.5
- New Mexico 5.NBT.B.5
- New York NY-5.NBT.5
- North Carolina NC.5.NBT.5
- North Dakota 5.NO.NBT.4
- Ohio 5.NBT.5
- Oregon 5.NBT.B.5
- Pennsylvania CC.2.1.5.B.2
- Rhode Island 5.NBT.B.5
- South Carolina 5.PAFR.1.1
- South Dakota 5.NBT.B.5
- Tennessee 5.NBT.B.5
- Texas 111.7.b.3.B
- Utah 5.NBT.5
- Vermont 5.NBT.B.5
- Virginia 5.CE.1b.i, 5.CE.1b.ii, 5.CE.1b.iii, 5.CE.1b.iv
- Washington 5.NBT.B.5
- West Virginia M.5.8
- Wisconsin M.5.NBT.B.5