Three factors, any order: 3rd grade math lesson

What this lesson shows

2 × 7 × 5 regrouped as 7 × (2 × 5) = 70.

The worked example

The lesson works this one step by step: 2 × 7 × 5. Then your kid tries one like it on paper.

The steps

Find an easy pair
Group it in parentheses
Multiply by the third

Helping at home

Look at all three factors before multiplying. Find a pair that is easy, like 2 and 5 making 10. Put that pair in parentheses, multiply it first, then multiply by the third factor.

If your kid gets stuck

Which two factors make an easy number?

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.)

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

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

Three factors, any order