Power match
Can you locate these values on this interactive logarithmic scale?
Age
16 to 18
Challenge level
Problem
In the interactivity below, you are given a target to position on a logarithmic scale. How close can you get to the target?
Teachers' Resources
Why do this problem?
This interactivity gives students an opportunity to become familiar with logarithmic scales.
Possible approach
This activity can be played in pairs as a game, or individually. When a flag is incorrectly placed, can students understand why? This is good for rooting out errors in understanding. For example, $10^{1.5}$ is not half way between 10 and 100.
Alternatively it could be used as a starter or plenary with the whole class working together on an interactive whiteboard to decide where to place the green dot for each target.
Key questions
Which two powers of ten will the target be between?
Which one is it closer to?
Which one is it closer to?
What is the value of the halfway point between two powers of ten?
Possible extension
Students could go on to explore scientific contexts for logarithms, such as the pH scale in the problem Mixing pH.
Possible support
A Question of Scale introduces logarithmic scales by inviting students to consider orders of magnitude of scientific quantities.