What this lesson shows
23 × 45 as four boxes, then the four products added.
The worked example
The lesson works this one step by step: 23 × 45. Then your kid tries one like it on paper.
The steps
- Break both numbers apart
- Draw four boxes and label them
- Multiply in each box
- Add the four products
Helping at home
Break both numbers into tens and ones, and draw four boxes. Say each box in place value: "2 tens times 4 tens is 8 hundreds". Add the four products at the end.
If your kid gets stuck
Break both numbers apart, then draw four boxes.
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 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.
Matches a standard in all 50 states and DCSee each state's code
- Alabama MA19.4.11a
- Alaska 4.NBT.5
- Arizona 4.NBT.B.5 *
- Arkansas 4.CAR.3
- California 4.NBT.B.5
- Colorado 4.NBT.B.5
- Connecticut 4.NBT.B.5
- Delaware 4.NBT.B.5
- District of Columbia 4.NBT.B.5
- Florida MA.4.NSO.2.2, MA.4.NSO.2.3, MA.4.NSO.2.5
- Georgia 4.NR.2.3
- Hawaii 4.NBT.B.5
- Idaho 4.NBT.B.5.a, 4.NBT.B.5.b
- Illinois 4.NBT.B.5
- Indiana 4.CA.1
- Iowa 4.NBT.B.5
- Kansas 4.NBT.5
- Kentucky KY.4.NBT.5
- Louisiana 4.NBT.B.5
- Maine 4.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
- Massachusetts 4.NBT.B.5
- Michigan 4.NBT.B.5
- Minnesota 3.1.2.5, 4.1.1.3, 4.1.1.4, 5.1.1.3
- Mississippi 4.NBT.5
- Missouri 4.NBT.A.6
- Montana MT.4.NBT.5, 4.D1.21, 4.D2.4, 4.D2.9
- Nebraska 4.A.1.b, 4.A.1.d
- Nevada 4.NBT.B.5
- New Hampshire 4.NBT.B.5
- New Jersey 4.NBT.B.5
- New Mexico 4.NBT.B.5
- New York NY-4.NBT.5
- North Carolina NC.4.NBT.5
- North Dakota 4.NO.NBT.5
- Ohio 4.NBT.5
- Oklahoma 3.N.2.8, 4.N.2.2, 4.N.2.3, 5.N.2.1
- Oregon 4.NBT.B.5
- Pennsylvania CC.2.1.4.B.2
- Rhode Island 4.NBT.B.5
- South Carolina 4.NR.1.2, 5.PAFR.1.1, 4.PAFR.1.3
- South Dakota 4.NBT.B.5
- Tennessee 4.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
- Utah 4.NBT.5
- Vermont 4.NBT.B.5
- Virginia 4.CE.2a, 4.CE.2g.i, 4.CE.2g.ii, 4.CE.2g.iii, 5.CE.1a
- Washington 4.NBT.B.5
- West Virginia M.4.10
- Wisconsin M.4.NBT.B.5, M.4.NBT.A.3
- Wyoming 4.NBT.5a, 4.NBT.5b, 4.NBT.5c, 4.NBTP.5.A, 4.NBTP.5.B, 4.NBTP.5.C