Maths- investigating the area of circles

Students realised that by squaring the circle’s radius, the resulting square ‘fits’ in the circle less than 4 times. Which number that we have been working with is somewhere less than 4 times? Well Pi of course or 3.14. From here students deduced that the formula for working out the area of the circle itself is the raduis x radius x pi…or pi.r(squared). In deriving the formula themselves students understand the area of a circle much deeper and can now try an estimating strategy to see if they get around the same answer!

 

Mathematics- circles

Many students are noticing that the diameter ‘fits’ into the circumference of a circle 3 and a bit times. The challenge has been to work out what that ‘bit’ is as a ratio of the diameter.

Many students are getting around 3.14 which is Pi. Students are now expressing the relationship between the diameter and the circumference and pi with a formula so that they can begin constructing their trundle wheels.