## The perfect lesson (how to teach scale drawing)

scale drawing |

Showing posts with label **area**. Show all posts

Showing posts with label **area**. Show all posts

scale drawing |

Estimation. How many bricks? |

It is easy to do and works, plus it allows you to escape the confines of the classroom.

I guess we have all heard the song 'The wall' by Pink Floyd. I enjoyed listening to it but was never quite sure about the lyrics.

At this time of year I think most teachers would prefer to listen to Alice Cooper, you know the song 'Schools Out'. Just to remind you about Pink Floyd’s lyric

Here is an idea that will get you plaudits
from those that like to see Maths in a context or ‘real life’ Maths. It will
give a different pace to your lessons and engage those who prefer a kinesthetic
learning style or experience. Yet again what you do depends upon your imagination and
perhaps appetite.

Eat lots of cereal. Ban toast for breakfast
and force, if you have to, your family to eat packets and packets of cereal.
Keep the boxes. No recycling. You have to supervise the opening of the boxes as
you want them to be in as good a condition as possible.

Organise the class into groups around
tables, 4 to a table seems to work. As the proud owner of numerous cereal
packets distribute one or more to each group. Ask the class what they could
find out about the boxes, give them a minute or two to jot down some ideas then
collect one from each table and record them on the board. It is now up you how
you progress. Sometimes I have collected the ideas from the class, recorded them on the board, and then discussed what we have to find. Alternatively I have collected the ideas but also handed out a worksheet to some classes listing what needs
to be found or what tasks they have to do. Here are some suggestions of what they have to do and record as a group.

Find the height, width and length of the
box.

Find the volume of the box.

Draw a net of the box to scale.

Make an isometric drawing of the box.

Find the surface area.

How much does the it cost per gram? per
100g?

How many boxes could fill the classroom?

What is the ratio of sugar to salt? Does it fit in with Government guidelines?

If it takes 10 days to eat a box how much
salt would I consume in a year?

There are always new and exciting ways to tackle topics. Buy this books and you will be generating even more ideas for yourself 100+ Ideas for Teaching Mathematics (Continuum One Hundreds)
.

As one reviewer says*'I was looking for a book which would inspire me when planning sessions for
teaching mathematics. I browsed a number of books but this one was definitely
the best as far as I could see on-line. When it arrived it was even better than
I expected. I would certainly recommend this book to anyone who teaches maths! '*

As one reviewer says

Alternatively you could work on the suggestions gathered from the class. The outcome could be report produced by each group or answers in their books from prepared worksheet by you.

You could provide them with boxes of the
same product but in different sizes which is the best value? I am sure you can
think of other ideas. Happy eating. (*By the way you have noticed a picture of porridge, I don't eat any other cereal these days, can't think why.)*

Those of you who read my post about how to use a frog to
solve equations might want to use this before that lesson. It can also be used
independently before starting to find the areas of complex shapes. It is
deceptively simple, but powerful.

All you need to do I draw two lines and on one put its
length, say 10cm, and on the other x cm and 8cm. Explain that the two lines are
the same length. Two frogs have a jumping competition, they agree to jump over
the same course of 10 cm. The first jumps the full 10 cm. Fred the frog jumps
but only a distance of x cm but then
covers the rest of the course, which is 8 cm. How far is x cm?

As you know this is really x + 8 = 10. Depending on the
level of pupils you can continue with further examples, make the link to
algebra or move on.

The next step (or jump if you are a frog) is to draw similar
lines such as one which is 10 cm and the
other which is x cm, x cm and 3 cm or whatever appeals to you. Again you can
use the story of the two frogs one jumping the full 10 cm the other Fred
covering x, cm then x cm then 3 cm. Emphasise that both x cm are the
exactly the same distance. Then ask how
far is x cm?

Of course the pupils are solving 2x + 3 = 10. You can judge
how far to take this idea it really does depend on the class or pupil. Use in
its simplest form before doing complex shapes as pupils often fail to grasp how
to find a missing dimension.

If you are wondering about previous mentions of Fred the
frog see my previous post ‘solving equations with a frog’.

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