What this lesson shows
174 + 253 is near 170 + 250 = 420. Check the exact answer against it.
The worked example
The lesson works this one step by step: 174 + 253. Then your kid tries one like it on paper.
The steps
- Round each number
- Add the round numbers
- Add exactly
- Close to the estimate?
Helping at home
Round each number to the nearest ten before you add, and add the round numbers in your head. Then add exactly. If the exact answer is far from the estimate, look for the slip.
If your kid gets stuck
Round each number 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.
Standards
- Common Core 3.NBT.A.2
Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.
Matches a standard in all 50 states and DCSee each state's code
- Alabama MA19.3.11, MA19.4.10
- Alaska 3.NBT.2, 4.NBT.4
- Arizona 3.NBT.A.2 *
- Arkansas 3.CAR.1, 4.CAR.2
- California 3.NBT.A.2
- Colorado 3.NBT.A.2
- Connecticut 3.NBT.A.2
- Delaware 3.NBT.A.2
- District of Columbia 3.NBT.A.2
- Florida MA.3.NSO.2.1
- Georgia 3.PAR.2.1, 3.PAR.2.2
- Hawaii 3.NBT.A.2
- Idaho 3.NBT.A.2, 4.NBT.B.4
- Illinois 3.NBT.A.2
- Indiana 3.CA.2, 3.CA.1
- Iowa 3.NBT.A.2, 4.NBT.B.4
- Kansas 3.NBT.2, 4.NBT.4
- Kentucky KY.3.NBT.2
- Louisiana 3.NBT.A.2
- Maine 3.NBT.A.2
- Maryland 3.NOS.D.7.a, 3.NOS.D.7.b, 3.NOS.D.7.c, 4.NOS.B.3.b
- Massachusetts 3.NBT.A.2
- Michigan 3.NBT.A.2
- Minnesota 3.1.2.1, 3.1.2.2
- Mississippi 3.NBT.2, 4.NBT.4
- Missouri 3.NBT.A.3, 4.NBT.A.5
- Montana MT.3.NBT.2, MT.4.NBT.4
- Nebraska 3.A.1.a, 4.A.1.a
- Nevada 3.NBT.A.2
- New Hampshire 3.NBT.A.2
- New Jersey 3.NBT.A.2, 4.NBT.B.4
- New Mexico 3.NBT.A.2
- New York NY-3.NBT.2
- North Carolina NC.3.NBT.2.a, NC.3.NBT.2.b, NC.3.NBT.2.c
- North Dakota 3.NO.NBT.3
- Ohio 3.NBT.2
- Oklahoma 3.N.2.3
- Oregon 3.NBT.A.2
- Pennsylvania CC.2.1.3.B.1
- Rhode Island 3.NBT.A.2
- South Carolina 3.PAFR.1.1, 4.PAFR.1.1, 3.PAFR.2.2
- South Dakota 3.NBT.A.2, 4.NBT.B.4
- Tennessee 3.NBT.A.2
- Texas 111.5.b.4.A, 111.5.b.5.A
- Utah 3.NBT.2
- Vermont 3.NBT.A.2
- Virginia 3.CE.1c, 3.CE.1e, 4.CE.1c
- Washington 3.NBT.A.2
- West Virginia M.3.13, M.4.9
- Wisconsin M.4.NBT.B.4, M.3.NBT.A.2
- Wyoming 3.NBT.2