One digit times two digits: 3rd grade math lesson

What this lesson shows

3 × 24 = 3 × (20 + 4) = 60 + 12.

The worked example

The lesson works this one step by step: 3 × 24. Then your kid tries one like it on paper.

The steps

Split into tens and ones
Multiply both parts
Add the parts

Helping at home

Split the two-digit number into tens and ones and write them in parentheses. The one-digit number multiplies both parts: say the tens part in tens, "3 times 2 tens is 6 tens". Then add the two parts.

If your kid gets stuck

Split it into tens and ones first.

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.

See how Lux works

Standards

Common Core 3.OA.B.5
Apply properties of operations as strategies to multiply and divide. Examples: If 6 × 4 = 24 is known, then 4 × 6 = 24 is also known. (Commutative property of multiplication.) 3 × 5 × 2 can be found by 3 × 5 = 15, then 15 × 2 = 30, or by 5 × 2 = 10, then 3 × 10 = 30. (Associative property of multiplication.) Knowing that 8 × 5 = 40 and 8 × 2 = 16, one can find 8 × 7 as 8 × (5 + 2) = (8 × 5) + (8 × 2) = 40 + 16 = 56. (Distributive property.)
Common Core 3.MD.C.7c
Use tiling to show in a concrete case that the area of a rectangle with whole-number side lengths a and b + c is the sum of a × b and a × c. Use area models to represent the distributive property in mathematical reasoning.

Matches a standard in all 50 states and DCSee each state's code

Alabama MA19.3.5, MA19.3.7a, MA19.3.22
Alaska 3.OA.5, 3.MD.9.c
Arizona 3.OA.B.5, 3.OA.C.7 *, 3.MD.C.7.c
Arkansas 3.CAR.2, 3.CAR.3
California 3.OA.B.5, 3.MD.C.7
Colorado 3.OA.B.5, 3.MD.C.7.c
Connecticut 3.OA.B.5, 3.MD.C.7
Delaware 3.OA.B.5, 3.MD.C.7
District of Columbia 3.OA.B.5, 3.MD.C.7
Florida MA.3.NSO.2.4, MA.3.AR.1.1
Georgia 3.PAR.3.3
Hawaii 3.OA.B.5, 3.MD.C.7
Idaho 3.OA.B.5, 3.OA.C.7.b, 3.MD.C.7.d
Illinois 3.OA.B.5, 3.MD.C.7
Indiana 4.CA.3, 3.CA.5, 3.CA.6, 3.CA.3
Iowa 3.OA.B.5, 3.OA.C.7, 3.MD.C.7.c
Kansas 3.OA.5, 3.OA.7, 3.MD.8.c
Kentucky KY.3.OA.5, KY.3.OA.7, KY.3.MD.7.c
Louisiana 3.OA.B.5, 3.MD.C.7.c
Maine 3.OA.B.5, 3.MD.C.7c
Maryland 3.NOS.C.4, 3.NOS.E.9.a, 3.NOS.E.9.b, 3.NOS.E.9.c, 4.NOS.C.7.a, 4.NOS.C.7.c, 3.GR.C.7.b
Massachusetts 3.OA.B.5, 3.MD.C.7.c
Michigan 3.OA.B.5, 3.MD.C.7
Minnesota 3.1.2.5, 5.2.2.1, 4.3.2.3
Mississippi 3.OA.5, 3.OA.7, 3.MD.7.c
Missouri 3.RA.B.6, 3.RA.C.7, 3.GM.C.14
Montana MT.3.OA.5, MT.3.MD.7.c, MT.3.MD.7.a, MT.3.MD.7.b
Nebraska 3.A.1.e, 3.A.1.g
Nevada 3.OA.B.5, 3.MD.C.7
New Hampshire 3.OA.B.5, 3.MD.C.7
New Jersey 3.OA.B.5, 3.M.B.5c
New Mexico 3.OA.B.5, 3.MD.C.7
New York NY-3.OA.5, NY-3.OA.7.a, NY-3.MD.7.c
North Carolina NC.3.OA.1.b, NC.3.MD.7.c
North Dakota 3.AR.OA.1, 3.AR.OA.2, 4.AR.OA.2, 5.AR.OA.1
Ohio 3.OA.5, 3.MD.7.c
Oklahoma 3.N.2.2, 3.N.2.8, 3.A.2.2, 5.A.2.1
Oregon 3.OA.B.5, 3.OA.C.7, 3.GM.C.7
Pennsylvania CC.2.2.3.A.2, CC.2.4.3.A.5
Rhode Island 3.OA.B.5, 4.OA.A.3.a, 3.MD.C.7.c
South Carolina 3.PAFR.1.3
South Dakota 3.OA.B.5, 3.OA.C.7.a, 3.OA.C.7.b, 3.MD.C.7.c
Tennessee 3.OA.B.5, 3.OA.C.7, 3.MD.C.7.c
Texas 111.5.b.4.F, 111.5.b.4.G, 111.5.b.6.C
Utah 3.OA.5, 3.OA.7.b, 3.MD.7.c
Vermont 3.OA.B.5, 3.MD.C.7
Virginia 3.CE.2c, 3.CE.2d, 3.CE.2f
Washington 3.OA.B.5, 3.MD.C.7
West Virginia M.3.5, M.3.7, M.3.24
Wisconsin M.3.OA.C.6, M.3.OA.B.4, M.3.MD.C.7
Wyoming 3.OA.7, 3.MD.7c, 3.MDP.7.C

One digit times two digits