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? multiply 1 A reciprocal in math is a number you multiply by so that the result is 1. product reciprocal pairs Two numbers whose product is 1 are called reciprocal pairs.

product 1 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

product 1 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

product 1! 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

reciprocals So, now that you know what reciprocals are – how do you find the reciprocal of a number? It’s so easy!!! When you hear reciprocal – RE-FLIP-RO-CAL!!! think RE-FLIP-RO-CAL!!!

You think because you simply the fraction to get the reciprocal!

Let’s practice finding the refliprocal – uh, I mean reciprocal – of some numbers

Some more –

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! whole number written as a fraction reciprocal

Let’s review what we’ve learned so far. Write the reciprocal for each fraction or whole number. 2/55/2 4 1/22/1 or 2 6/10 1/3 10/6 3/1 or 3 1/ /12 1/55 1/47

Let’s review what we’ve learned so far. Find the missing fraction for each number sentence x = 1? 13 1 x ? =

Let’s review what we’ve learned so far. Find the missing fraction for each number sentence x = 1? 70 1 x ? =

There’s one more part to today’s lesson— reciprocal mixed number What to do when finding the reciprocal of a mixed number ? Write the mixed number as an improper fraction Flip the improper fraction 5 ⅓ = 16 3 Now FLIP the improper fraction: 3 16 reciprocal

Let’s practice finding the refliprocal of some mixed numbers Improper Fraction: Reciprocal

Let’s practice finding the refliprocal of some mixed numbers Improper Fraction: Reciprocal

Let’s review what we’ve learned so far. Find the missing fraction for each number sentence. 1 5 x = 1? 7 1 x ? =