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18 
Evaluating powers and roots of numbers. Calculator use for squared, cubed, higher powers, square root, cube root, higher roots. Reciprocal of a number, including fractions Activity Khan Video Tutorial: Reciprocal  Powers  Powers 2  Square Root 
p333 Ex 23.03 p9, Ex 1.05 NuLake p39, 40, 41, 42, 43

Meaning 
We say 
Calculator 
Answer 
4x4x4x4x4 = 4^{5} 
"4 to the power 5" 
4^{5 }= 1024 

7x7x7x7 = 7^{4} 
"7 to the power 4 " 
7^{4} = 2401 

9x9 = 9^{2} 
"9 squared" 
9^{2} = 81 

5x5x5 = 5^{3} 
"5 cubed" 
5^{3} = 125 
Meaning 
We say 
Calculator 
Answer 

? x ? = 64 
Square root of 64 
= 8 

? x ? x ? = 27 
Cube root of 27 
or 
= 3 

?x?x?x?x?=243 
Fifth root of 243 
or 
= 3 
5 squared? 
NOT = 25 
Correct = 25 
3 to the power of 4 
NOT = 81 
Correct = 81 
Calculator does the power before the negative. BRACKETS enclosing the negative are needed.

Reciprocal of N 

The reciprocal is the power of 1 
= N^{1} 
Or the result of dividing the number into 1 
= 1 ÷ N 
eg The Reciprocal of 4 = ^{1}/_{4} 

eg The Reciprocal of ^{3}/_{5} = ^{5}/_{3} 

eg The Reciprocal of 0.125 = 8 