What this lesson shows
4/10 + 25/100: rename 4/10 as 40/100 first.
The worked example
The lesson works this one step by step: 4/10 + 25/100. Then your kid tries one like it on paper.
The steps
- Tenths and hundredths are different sizes
- Rename the tenths as hundredths
- Add the tops
- The bottom stays 100
Helping at home
First rename the tenths as hundredths: each tenth is 10 hundredths. Then add the tops and keep 100 on the bottom. A 10 × 10 grid helps check the sum.
If your kid gets stuck
Rename the tenths as hundredths 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 4.NF.C.5
Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this technique to add two fractions with respective denominators 10 and 100. For example, express 3/10 as 30/100, and add 3/10 + 4/100 = 34/100.
Matches standards in 43 statesSee each state's code
- Alabama MA19.4.17a
- Alaska 4.NF.5
- Arizona 4.NF.C.5
- Arkansas 4.NPV.9
- California 4.NF.C.5
- Colorado 4.NF.C.5
- Connecticut 4.NF.C.5
- Delaware 4.NF.C.5
- District of Columbia 4.NF.C.5
- Florida MA.4.FR.1.1, MA.4.FR.2.3
- Georgia 4.NR.5.1
- Hawaii 4.NF.C.5
- Idaho 4.NF.C.5
- Illinois 4.NF.C.5
- Iowa 4.NF.C.5
- Kansas 4.NF.5
- Kentucky KY.4.NF.5.a, KY.4.NF.5.b
- Louisiana 4.NF.C.5
- Maine 4.NF.C.5
- Maryland 4.NOS.F.14
- Massachusetts 4.NF.C.5
- Michigan 4.NF.C.5
- Mississippi 4.NF.5
- Montana MT.4.NF.5, 4.D3.6, 4.D4.3
- Nevada 4.NF.C.5
- New Hampshire 4.NF.C.5
- New Jersey 4.NF.C.5
- New Mexico 4.NF.C.5
- New York NY-4.NF.5
- North Carolina NC.4.NF.6.a, NC.4.NF.6.b
- North Dakota 4.NO.NF.1
- Ohio 4.NF.5
- Oregon 4.NF.C.5
- Pennsylvania CC.2.1.4.C.3
- Rhode Island 4.NF.C.5
- South Carolina 4.PAFR.2.2
- South Dakota 4.NF.C.5
- Tennessee 4.NF.C.5
- Utah 4.NF.5
- Vermont 4.NF.C.5
- Washington 4.NF.C.5
- West Virginia M.4.16
- Wisconsin M.4.NF.C.5