What this lesson shows
Fixes a mistake
2 × 1.2 is 2.4, not 24: 2 × 12 tenths is 24 tenths.
The worked example
The lesson works this one step by step: 2 × 1.2. Then your kid tries one like it on paper.
The steps
- Estimate first
- Say it in tenths
- Place the point, and check
Helping at home
Estimate first: 1.2 is between 1 and 2, so 2 × 1.2 is between 2 and 4. Then say the decimal in tenths: 2 × 12 tenths is 24 tenths, 2.4. The answer must agree with the estimate.
If your kid gets stuck
Estimate first, then say it in tenths.
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.7
Add, subtract, multiply, and divide decimals to hundredths, 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 and explain the reasoning used.
Matches a standard in all 50 states and DCSee each state's code
- Alabama MA19.5.8a, MA19.5.8b
- Alaska 5.NBT.7
- Arizona 5.NBT.B.7 *
- Arkansas 5.CAR.3, 5.CAR.4
- California 5.NBT.B.7
- Colorado 5.NBT.B.7
- Connecticut 5.NBT.B.7
- Delaware 5.NBT.B.7
- District of Columbia 5.NBT.B.7
- Florida MA.5.NSO.2.3, MA.5.NSO.2.4, MA.5.M.2.1
- Georgia 5.NR.4.4
- Hawaii 5.NBT.B.7
- Idaho 5.NBT.A.7.a, 5.NBT.A.7.b
- Illinois 5.NBT.B.7
- Indiana 5.CA.9, 5.CA.10
- Iowa 5.NBT.B.7
- Kansas 5.NBT.7
- Kentucky KY.5.NBT.7.a, KY.5.NBT.7.b
- Louisiana 5.NBT.B.7
- Maine 5.NBT.B.7
- Maryland 5.NOS.B.4.a, 5.NOS.B.5.a, 5.NOS.B.6.b, 5.NOS.B.6.c, 5.NOS.B.6.d, 5.NOS.B.7.a, 5.NOS.B.7.b, 5.NOS.B.7.c, 5.NOS.B.7.d, 5.NOS.B.7.e
- Massachusetts 5.NBT.B.7
- Michigan 5.NBT.B.7
- Minnesota 5.1.1.3, 5.1.3.1, 5.1.3.2, 5.1.3.4
- Mississippi 5.NBT.7
- Missouri 5.NBT.A.6, 5.NBT.A.7, 5.NBT.A.8, 5.NF.B.4, 5.RA.C.5
- Montana MT.5.NBT.7, 5.D1.11, 5.D1.12, 5.D1.13, 5.D2.11, 5.D2.12
- Nebraska 5.N.3.g, 5.A.1.c
- Nevada 5.NBT.B.7
- New Hampshire 5.NBT.B.7
- New Jersey 5.NBT.B.7
- New Mexico 5.NBT.B.7
- New York NY-5.NBT.7
- North Carolina NC.5.NBT.7.a, NC.5.NBT.7.b, NC.5.NBT.7.c, NC.5.NBT.7.d
- North Dakota 5.NO.NBT.5
- Ohio 5.NBT.7.a, 5.NBT.7.b, 5.NBT.7.c
- Oklahoma 5.N.2.1, 5.N.3.2, 5.N.3.3
- Oregon 5.NBT.B.7
- Pennsylvania CC.2.1.5.B.2
- Rhode Island 5.NBT.B.7
- South Carolina 5.PAFR.1.4, 5.PAFR.1.3
- South Dakota 5.NBT.B.7.a, 5.NBT.B.7.b
- Tennessee 5.NBT.B.7
- Texas 111.6.b.4.A, 111.7.b.3.A, 111.7.b.3.D, 111.7.b.3.E, 111.7.b.3.F, 111.7.b.3.G, 111.7.b.3.K
- Utah 5.NBT.7
- Vermont 5.NBT.B.7
- Virginia 4.CE.4a.i, 4.CE.4a.ii, 4.CE.4b, 5.CE.3a, 5.CE.3b.i, 5.CE.3b.ii, 5.CE.3b.iii, 5.CE.3c.i, 5.CE.3c.ii, 5.CE.3c.iii, 5.CE.3c.iv, 5.CE.3d, 5.CE.3e
- Washington 5.NBT.B.7
- West Virginia M.5.10
- Wisconsin M.5.NBT.A.4, M.5.NBT.B.7
- Wyoming 5.NBT.7