What this lesson shows
Fixes a mistake
5 × 80 is 40 tens, 400, not 40. The fact already ends in 0.
The worked example
The lesson works this one step by step: 5 × 80. Then your kid tries one like it on paper.
The steps
- Check the size first
- Say it in tens
- Write what the tens make
Helping at home
Before multiplying, guess the size: 5 × 80 is more than 5 × 10. Then say it in tens: 5 × 8 tens is 40 tens, which is 400. Check the answer against the guess.
If your kid gets stuck
Is it more than the digit times 10?
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 3.NBT.A.3
Multiply one-digit whole numbers by multiples of 10 in the range 10-90 (e.g., 9 × 80, 5 × 60) using strategies based on place value and properties of operations.
Matches standards in 46 statesSee each state's code
- Alabama MA19.3.12
- Alaska 3.NBT.3
- Arizona 3.NBT.A.3
- Arkansas 3.CAR.4
- California 3.NBT.A.3
- Colorado 3.NBT.A.3
- Connecticut 3.NBT.A.3
- Delaware 3.NBT.A.3
- District of Columbia 3.NBT.A.3
- Florida MA.3.NSO.2.3
- Georgia 3.PAR.3.5
- Hawaii 3.NBT.A.3
- Idaho 3.NBT.A.3
- Illinois 3.NBT.A.3
- Iowa 3.NBT.A.3
- Kansas 3.NBT.3
- Kentucky KY.3.NBT.3
- Louisiana 3.NBT.A.3
- Maine 3.NBT.A.3
- Maryland 3.NOS.D.8, 4.NOS.B.4
- Massachusetts 3.NBT.A.3
- Michigan 3.NBT.A.3
- Mississippi 3.NBT.3
- Missouri 3.NBT.A.4
- Montana MT.3.NBT.3
- Nebraska 3.A.1.h
- Nevada 3.NBT.A.3
- New Hampshire 3.NBT.A.3
- New Jersey 3.NBT.A.3
- New Mexico 3.NBT.A.3
- New York NY-3.NBT.3
- North Carolina NC.3.NBT.3
- North Dakota 3.NO.NBT.4
- Ohio 3.NBT.3
- Oregon 3.NBT.A.3
- Pennsylvania CC.2.1.3.B.1
- Rhode Island 3.NBT.A.3
- South Carolina 4.PAFR.1.2
- South Dakota 3.NBT.A.3
- Tennessee 3.NBT.A.3
- Texas 111.6.b.4.B
- Utah 3.NBT.3
- Vermont 3.NBT.A.3
- Washington 3.NBT.A.3
- West Virginia M.3.14
- Wisconsin M.3.NBT.A.3
More in this unit
- Equal groups and arrays
- Groups or how many in each?
- Two kinds of division
- Equal jumps on a number line
- Turn the array
- Facts from facts you know
- Add the parts
- One digit times two digits
- Multiply both parts
- Three factors, any order
- Times tens and hundreds
- One array, four facts
- True or false?
- The answer can go first
- The unknown anywhere
- Even or odd?
- The ones digit decides
- Is it a multiple?
- A number is its own multiple
- Patterns from a rule
- Position is not value
- Two-step word problems
- Finish the second step
- One pattern, two ways