Problem

Can you arrange some of these logarithms to complete the grid below? The values of the logarithms need to increase along the rows and down the columns. Try to do this without using a calculator.

\(\log_{3} 2\)

\(\log_{4} 5\)

\(\log_{2} 5\)

\(\log_{3} 4\)

\(\log_{3} 5\)

\(\log_{5} 3\)

\(\log_{2} 3\)

\(\log_{5} 2\)

\(\log_{5} 4\)

\(\log_{4} 3\)

\(\log_{4} 2\)

\(\log_{2} 4\)

You might find it helpful to think about the following questions:

  • Can you put pairs of logarithms from the list in order of size?
  • Which logarithms are bigger than \(1\) and which ones are smaller?

Which is bigger:

  • \(\log_{2} 5\) or \(\log_{2} 3\)?
  • \(\log_{2} 5\) or \(\log_{3} 5\)?

Can you explain why this inequality is true?

\[\log_{5} 2 < 1 < \log_{2} 5\]

You could do this by thinking about what \(\log_{5} 2\) means or by thinking about how you could write \(1\) as a logarithm.

Can you use the same logarithms to complete this grid too?

\(\log_{3} 2\)

\(\log_{4} 5\)

\(\log_{2} 5\)

\(\log_{3} 4\)

\(\log_{3} 5\)

\(\log_{5} 3\)

\(\log_{2} 3\)

\(\log_{5} 2\)

\(\log_{5} 4\)

\(\log_{4} 3\)