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This self-paced tutorial explains how to use number lines to recognize and generate equivalent fractions. Learn how to break segments into smaller pieces to find equivalent fractions.
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How to Use Number Lines to Find Equivalent Fractions Dawn Galente, Arlington CSD 2012 This is a self-paced tutorial. Click the screen each time you want to see the next step. Click to Start
Standard 4.NF.1 Explain why a fraction a/b is equivalent to a fraction (n x a)/(n x b) by using visual fraction models….use this principle to recognize and generate equivalent fractions. Start with a simple fraction like 1/3. 5 2 1 1 1 3 2 2 4 3 6 3 0 6 6 6 6 3 3 3 3 6 3 6 3 Picture what this number line would look like if we broke each segment into 2 equal pieces. What fraction would this new line represent? Now 2 out of 6 segments are shaded… 2/6. 0 0
I can find any number of equivalent fractions by simply breaking each segment on the line into smaller pieces. 0 Start with 1/2… 1 8 6 2 7 3 4 1 5 2 2 break each piece into 4 equal pieces… 8 8 8 8 8 8 8 8 2 0 to get 4/8. I have four times as many shaded segments now; 1 x 4= 4. x4 1 x4 4 2 = 8 I have four times as many total segments now… 2 x 4 = 8.
What if I want to find a specific equivalent fraction? ? 3 = Start with a model of the first fraction. 5 10 Think: I have 5 total segments now. I need 10 total segments. 1 2 3 4 0 5 5 5 5 5 5 How can I break 5 segments into smaller segments so that I have 10? 9 6 8 1 7 4 5 3 2 10 0 10 10 10 10 10 10 10 10 10 10 Break them into 2 segments each! x2 6 3 = x2 5 10 How many shaded segments do I have now? 3 x 2 = 6.
a/b is equivalent to (n × a)/(n × b) means….. 0 1 8 6 7 5 3 1 4 2 2 2 8 8 8 8 8 8 8 8 2 0 x4 4 1 1 = = x4 8 2 2 x n a a = x n b b