### Why do this problem?

This activity gives practice in working with powers of 10 and
tests awareness of relative sizes of physical objects encountered
in scientific contexts. The numbers are given in scientific notion,
such as 1.2e3 for 1200 or 26e-3 for 0.026, the familiarity with
which is essential in the sciences.

You can print out this activity for

use on cards if you
wish.

### Possible approach

The activity could work well as a starter activity with
students working individually on computers or working
collaboratively to try to place the objects on the scale with as
few wrong answers as possible. Alternatively, it could be played
competitively with pairs of students taking it in turns to place
the objects and checking to see if they are right. There is the
opportunity for lots of discussion to justify where students wish
to place things on the scale, referring to sizes they know and
deciding whether the named objects are smaller or larger.

The activity generates a variety of questions so could be used
over a series of lessons with students trying to beat their best
scores, helping them to build up a fluency with powers of 10 and a
better awareness of the size of things.

There are various levels at which the activity could be used.
First students could look at the list of scientific quantities and
disentangle which of them they first of all recognise and,
secondly, which of them they could place on the scale. Once the
easier ones are placed students could take it in turns to take
sensible guesses with the harder ones, adjusting the answers in
turn until the cards are correctly placed. Finally, the numbers
could be revealed to allow the placement of the most difficults
cards. This is still non-trivial because quantities are given in
standard forms such as 260e-9 (260 nanometres) which would
correspond to 2.6e-7.

### Key questions

Are there any objects in the list whose size I am fairly sure
about?

Is this object bigger or smaller than a metre? How much bigger
or smaller?

### Possible extension

### Possible support

Start by arranging the objects whose size is well known, and use
the checking facility to see how many are right so far. Then
gradually add in the others.