## Coffs Harbour Public School Blog

Courtesy & Honour – Principal:Leonie Buehler

# iPad Circle Hunt Stage 3

Also a big thank you to Ms Jacka for supporting class 5M on Thursday.

Here are the tasks they were set:
Using a ruler, measure the radius of the various circles. Then use the formulas you have been shown to calculate the diameter, circumference and area of each circle. Don’t forget to label your units and add squared ² onto an area.  If you finish all of these go to your iPad and Star Walk App and ‘Sky Live’ to locate the names of the four planets rising . You need to find the radius, length of year (Earth years), and surface temperature (Celsius) of each planet.

Formulas:

• Pi: π=3.14
• Diameter:  d=2r (radius x 2)
• Circumference: C=πd (diameter x 3.14)
• Area: a =πr² (radius squared x 3.14)
An example would be: A circle has a radius of 6cm therefore 6 + 6 = 12cm, and the diameter is 12 cm. The circumference is then 12 x 3.14 (pi) = 37.68cm. Finally the area is calculated 6 x 6 = 36cm and 36cm x 3.14 (pi) = 113.04cm2 ( area always has a squared symbol).

The idea for this lesson came from a great teacher in America called Mr Avery and the link to his excellent class blog is in the blogroll. Here is the link to his blog post about The great Circle Hunt of 2012.

Mrs Booth

Do you use iPads for maths?