014. Powers and Index Notation
Learning Intentions
- To know the meaning of the terms: powers, index form, basic numeral, base number and index number
- To understand what
means when and are whole numbers - write a product in index form if there are repeated factors
- evaluate numeric expressions involving powers using multiplication
Pre-requisite Summary
- Understanding multiplication as repeated addition
- Knowledge of multiplication facts
- Understanding repeated multiplication (e.g.
) - Ability to multiply whole numbers
- Understanding mathematical notation and brackets
Worked Examples
Worked Example 1
Identify the terms in:
a)
b)
Worked Example 2
Write in expanded form:
a)
b)
c)
Worked Example 3
Write in index form:
a)
b)
c)
Worked Example 4
Evaluate using multiplication:
a)
b)
c)
Worked Example 5
Evaluate expressions involving powers:
a)
b)
c)
Problems
Problem 1
Identify the terms:
a)
b)
Problem 2
Write in expanded form:
a)
b)
c)
Problem 3
Write in index form:
a)
b)
c)
Problem 4
Evaluate:
a)
b)
c)
Problem 5
Evaluate expressions:
a)
b)
c)
Exercises
Understanding and Fluency
-
Identify base and index:
a)
b)
c) -
Write in expanded form:
a)
b)
c) -
Write in index form:
a)
b)
c) -
Evaluate powers:
a)
b)
c) -
Evaluate expressions:
a)
b)
c) -
Mixed practice:
a)
b)
c)
Reasoning
-
Explain what
means in words. -
A student says
. Explain the mistake. -
Compare
and . Which is larger? Explain. -
Why is
equal to ?
Problem-solving
-
A cube has side length
. The volume is . Evaluate the volume. -
A square has side length
. The area is . Find the area. -
Find the value of
. -
A number is written as
. Write this as repeated multiplication and evaluate. -
Evaluate
.
Potential Misunderstandings
- Students may think
means - Students may confuse base and index
- Students may stop multiplying too early when expanding powers
- Students may incorrectly write repeated multiplication in index form
- Students may evaluate multiplication before powers incorrectly
- Students may think
instead of