What this lesson shows
One number line cut two ways: 2/5 and 4/10 land on the same point.
The worked example
The lesson works this one step by step: 2/5 = ?/10. Then your kid tries one like it on paper.
The steps
- Mark the fraction
- Cut every part again
- Same point, same amount
- Multiply top and bottom by the same number
Helping at home
Draw a number line cut into the first fraction’s parts and mark it. Cut each part again and count to the same point. The number of parts and the parts counted both grow by the same times.
If your kid gets stuck
How many times as many parts?
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.A.1
Explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b) by using visual fraction models, with attention to how the number and size of the parts differ even though the two fractions themselves are the same size. Use this principle to recognize and generate equivalent fractions.
Matches a standard in all 50 states and DCSee each state's code
- Alabama MA19.4.13a
- Alaska 4.NF.1
- Arizona 4.NF.A.1 *
- Arkansas 4.NPV.8
- California 4.NF.A.1
- Colorado 4.NF.A.1
- Connecticut 4.NF.A.1
- Delaware 4.NF.A.1
- District of Columbia 4.NF.A.1
- Florida MA.4.FR.1.3
- Georgia 4.NR.4.1
- Hawaii 4.NF.A.1
- Idaho 4.NF.A.1
- Illinois 4.NF.A.1
- Indiana 4.NS.3
- Iowa 4.NF.A.1
- Kansas 4.NF.1
- Kentucky KY.4.NF.1.a, KY.4.NF.1.b
- Louisiana 4.NF.A.1
- Maine 4.NF.A.1
- Maryland 4.NOS.D.9.a, 4.NOS.D.9.b
- Massachusetts 4.NF.A.1
- Michigan 4.NF.A.1
- Minnesota 4.1.2.1
- Mississippi 4.NF.1
- Missouri 4.NF.A.1, 4.NF.A.2, 5.NF.B.5.d
- Montana MT.4.NF.1, 4.D1.7, 4.D1.25, 4.D3.2
- Nebraska 4.N.2.b
- Nevada 4.NF.A.1
- New Hampshire 4.NF.A.1
- New Jersey 4.NF.A.1
- New Mexico 4.NF.A.1
- New York NY-4.NF.1
- North Carolina NC.4.NF.1
- North Dakota 4.NO.NF.2, 4.NO.NF.3, 4.NO.NF.4
- Ohio 4.NF.1
- Oklahoma 4.N.3.1
- Oregon 4.NF.A.1
- Pennsylvania CC.2.1.4.C.1
- Rhode Island 4.NF.A.1
- South Carolina 4.NR.2.3, 5.PAFR.3.2
- South Dakota 4.NF.A.1
- Tennessee 4.NF.A.1
- Texas 111.6.b.3.C
- Utah 4.NF.1
- Vermont 4.NF.A.1
- Virginia 4.NS.3e
- Washington 4.NF.A.1
- West Virginia M.4.12
- Wisconsin M.4.NF.A.1
- Wyoming 4.NF.1
More in this unit
- Change both parts, not one
- Comparing with 1/2
- Comparing with a common denominator
- Bigger numbers, not a bigger fraction
- Fractions greater than one
- Breaking a fraction into parts
- Adding and subtracting like fractions
- Why the denominator stays
- Adding mixed numbers
- Subtracting mixed numbers
- Fraction stories, same whole
- A whole number times a fraction
- Multiply only the top
- A fraction of a number
- Fraction times stories
- Simplest form