1. Reciprocals A reciprocal is the value used to multiply a number by to make the product 1 Find the reciprocal of 2: 2 x = 1 What do we multiply 2 by to get a product of 1? 1212 Find the reciprocal of 3: 3 x = 1 What do we multiply 3 by to get a product of 1? 1313 Find the reciprocal of 10: 10 x = 1 What do we multiply 10 by to get a product of 1? 1 10 Why? Think of multiplying fractions 2 x = = 1 1212 2222 Multiplication is commutable x = 1 1212 Find the reciprocal of : 1212 2

2. Reciprocals 3 x = 1 4 4343 Find the reciprocal of : 3434 What do we multiply by to get a product of 1? 3434 Remember how to multiply fractions: 3 x = 12 = 1 4 12 4343 Find the reciprocal of 0.7 : 7 10 0.7 = 7 x = 1 10 7 Now change into a mixed number 10 7 1 3737 So the reciprocal of 0.7 is 1 3737

3. Reciprocals Find the reciprocal of 2 2323 First write the mixed number as a top heavy fraction then follow the same process 3838 Now you know the principles the shortcut to finding a reciprocal is to swap the numerator and denominator over 8 3 8 3 x = 1 8383

4. Reciprocals Now do these Find the reciprocals of: 1.67. 2.78. 0.3 3.0.259. 0.125 4.10. 1 5.11. 1.25 6.12. 1.6 1818 1 12 2727 3 11 3434. 1616 1717 4747 3535 4545 4 8 12 1212 3 2323 3 1313 3 8