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7 6. 1 5. 4. 2 9 . 38 9. 6 7. 5. Reciprocals. I can… find reciprocals of fractions, whole numbers, and mixed numbers. What is a reciprocal? Webster’s dictionary defines the word as “done, given, or felt equally on both sides”.
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7 6 1 5 4 2 9 38 9 6 7 5 Reciprocals I can… find reciprocals of fractions, whole numbers, and mixed numbers.
What is a reciprocal? Webster’s dictionary defines the word as “done, given, or felt equally on both sides”. Examples: The two countries made a reciprocal trade agreement. The two business partners had a reciprocal friendship based on respect for each other.
But what does the word reciprocal mean in math? A reciprocal in math is a number you multiply by so that the result is 1. Two numbers whose product is 1 are called reciprocal pairs.
Let’s look at some reciprocal pairs. Notice how when we multiply them, the product is 1. 5 and 1/5 26 and 1/26 1/9 and 9
Here’s more examples of reciprocal pairs. Again, notice how when we multiply them, the product is 1. 2/3 and 3/2 4/15 and 15/4 8/3 and 3/8
One last look at reciprocal pairs. You’re catching on!!! The product is 1! 2 ½ and 2/5 6 ⅗ and 5/33 7 ⅔ and 3/23
So, now that you know what reciprocals are – how do you find the reciprocal of anumber? It’s so easy!!! When you hear reciprocal – think RE-FLIP-RO-CAL!!!
RE – FLIP – RO - CAL FLIP You think because you simply the fraction to get the reciprocal!
Let’s practice finding the refliprocal – uh, I mean reciprocal – of some numbers. 4 15 1 6
Some more – 26 9 4 31
whole number written as a fraction reciprocal What if it’s a whole number? Write the whole number as a fraction, then FLIP it! 7 33
whole number written as a fraction reciprocal If it’s a whole number, write the whole number as a fraction, then FLIP it! 16 57
2/5 5/2 4 1/4 Let’s review what we’ve learned so far. Write the reciprocal for each fraction or whole number. 1/2 2/1 or 2 12 1/12 6/10 10/6 55 1/55 1/3 3/1 or 3 47 1/47
4 9 ? 1 = x Let’s review what we’ve learned so far. Find the missing fraction for each number sentence. ? 1 13 x =
1 5 ? 1 = x Let’s review what we’ve learned so far. Find the missing fraction for each number sentence. ? 1 70 x =
reciprocal There’s one more part to today’s lesson— What to do when finding the reciprocal of a mixed number? Write the mixed number as an improper fraction Flip the improper fraction 3 16 16 3 Now FLIP the improper fraction: 5 ⅓ =
Improper Fraction: Reciprocal 2 8 3 Let’s practice finding the refliprocal of some mixed numbers. 10 6 1 7 4 5
Improper Fraction: Reciprocal 2 3 7 Let’s practice finding the refliprocal of some mixed numbers. 30 4 1 20 1 2
1 5 4 ? 1 = x Let’s review what we’ve learned so far. Find the missing fraction for each number sentence. 3 10 1 ? 7 x =