Mathematical Investigation

Lamp Posts

In a village there are three streets. All the streets are straight. One lamp-post is put up at each cross-roads.

What is the greatest number of lamp-posts that could be needed?

Now try for four streets and five streets, can you see a pattern?

[See also Rod Triangles]

Investigate further.....

Investigations Home

Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for those learning Mathematics anywhere in the world. Click here to enter your comments.

A mathematical investigation is quite different to other mathematical activities. The best investigations are open ended and allow students to choose the way they work and how they record their findings. It is one of the few occasions when 'going off on a tangent' is not only acceptable but actively encouraged (within reason).

Students may ask for 'the answers' but this supposes that the activity is closed. Investigations can always be extended by varying the initial instructions or asking the question 'what if...?'. Sometimes students point out that the instructions are ambiguous and can be interpreted in different ways. This is fine and the students are encouraged to explain how they interpreted the instructions in their report.

Some students may benefit from a writing frame when producing the reports of their investigations. Teachers may suggest sections or headings such as Introduction, Interpretation, Research, Working and Conclusion or something similar.

Here are some other activities you may be interested in:

Featured Activity

Suko Sujiko

Suko Sujiko

Interactive number-based logic puzzles similar to those featuring in daily newspapers designed to develop numeracy skills. These puzzles are drag and drop and can earn you a Transum Trophy.

Suggested

Remainder Race

Remainder Race

A game involving chance and choice requiring an ability to calculate the remainder when a two digit number is divided by a single digit number.

The short web address is:

Transum.org/go/?to=remainder

Recently Updated

Shape Sorter

Shape Sorter

Drag each shape into the correct bin according to their types and symmetries. So far this activity has been accessed 269 times and 147 Transum Trophies have been awarded for completing it.

Teacher's notes for this investigation and solutions to Transum puzzles, exercises and activities are available when you are signed in to your Transum subscription account. If you do not yet have an account and you are a teacher, tutor or parent you can apply for one by completing the form on the Sign Up page.

A Transum subscription also gives you access to the 'Class Admin' student management system, downloadable worksheets, many more teaching resources and opens up ad-free access to the Transum website for you and your pupils.

Transum.org is a proud supporter of the kidSAFE Seal Program