    #### 3.   Reduce the surd √324

 (a) List the perfect squares 4     9    25     36    49     64     81 (b) From (a) the GREEN ones below are factors of 324 4     9    25     36    49     64     81 (c) From (b) choose the largest perfect square 81 (d) Carry on as before
 √324 = √(81 × 4) = 9√4 = 9 × 2 = 18

#### 4.   Simplify the surd √396

 (a) List the perfect squares 4     9    25     36    49     64     81 (b) From (a) the GREEN ones below are factors of 396 4     9    25     36    49     64     81 (c) From (b) choose the largest perfect square 36 (d) Carry on as before
 √396 = √(36 × 11) = 6√11

#### 5.   Reduce the surd √900

 (a) List the perfect squares 4     9    25     36    49     64    81     100 (b) From (a) the GREEN ones below are factors of 900 4     9    25     36    49     64     81     100 (c) From (b) choose the largest perfect square 100 (d) Carry on as before
 √900 = √(100 × 9) = 10√9 = 10 × 3 = 30

#### 6.   Simplify the surd √960

 (a) List the perfect squares 4     9    25     36    49     64     81 (b) From (a) the GREEN ones below are factors of 960 4     9    25     36    49     64     81 (c) From (b) choose the largest perfect square 64 (d) Carry on as before
 √960 = √(64 × 15) = 8√15

#### 7.   Reduce the surd √5120

 (a) List the perfect squares 4     9    25     36    49     64     81 (b) From (a) the GREEN ones below are factors of 5120 4     9    25     36    49     64     81 (c) From (b) choose the largest perfect square 64 (d) Carry on as before
 √5120 = √(64 × 80) = 8√80 = 8√(4 × 20) = 8.2√20 = 16√(4 × 5) = 16.2√5 = 32√5

#### 8.   Simplify the surd √3675

 (a) List the perfect squares 4     9    25     36    49     64     81 (b) From (a) the GREEN ones below are factors of 3675 4     9    25     36    49     64     81 (c) From (b) choose the largest perfect square 49 (d) Carry on as before
 √3675 = √(49 × 75) = 7√75 = 7√(25 × 3) = 7.5√3 = 35√3 back to:   