What this lesson shows
1,834 × 23 with the standard algorithm, each row said in place value, checked against 1,800 × 20.
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 first
- Multiply by the ones
- Write a 0, then multiply by the tens
- Add the two rows, and check
Helping at home
Estimate first: round the top number to the nearest hundred and the bottom one to the nearest ten. Say each product in place value: "2 tens times 8 hundreds is 16 thousands". Cross out the first row's carries before the second row, then check the answer against the estimate.
If your kid gets stuck
Estimate first, and cross out the first row’s carries before 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.
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