Friday, July 24, 2009

Mathematics Alive! Real Life Maths

@ Clementi Town Secondary School (by Venkataraman Swaminathan)

Activity 1: Your Age by Chocolate Math

  • Click HERE to see activity
  • This is similar to the Ghost Whisperer!
  1. First of all, pick the number of times a week that you would like to have chocolate (more than once but less than 10) (i.e. n)
  2. Multiply this number by 2 (just to be bold) (i.e. 2n)
  3. Add 5 (i.e. 2n+5)
  4. Multiply it by 50 -- I'll wait while you get the calculator (i.e. 50(2n + 5))
  5. If you have already had your birthday this year add 1759.If you haven't, add 1758.
  6. Now subtract the four digit year that you were born.
  7. You should have a three digit number
  8. The first digit of this was your original number (i.e., how many times you want to have chocolate each week).
  9. The next two numbers are
    YOUR AGE! (Oh YES, it is!!!!!)

Example: Connectedness for right-angled triangles

  • cos, sin, tan
  • one angle is equal to 90 degrees. 2 remaining angles not necessary equal.

Real Life Activities

1. Marina's Fish Shop [Quadratic Equations]

The task: The re-size the square and the isceleous triangle gives the least area (minimise lighting)

2. World Population Study [Exponential]

  • Using different "Family" configuration to prompt students to think

Others in the handout:

3. A Real Problem [Scaffolding worksheet]

4. Taxi Taxi [Coordinate Geometry]

5. Linear Equations in the Real World

6. A real scenario [Coordinate Geometry]

Using Geogebra to investigate the various possibilities
The 3 points are: BSS (4, 6); FTSS (-5, 1), BHSS (-2, -5)
To find the point which is equi-distant from the 3 locations.

1st exploration: When the perpendicular lines of all the sides of the triangles intersect

In the next investigation, draw Pink lines which are angle bisectors. And eventually dark blue lines which are just perpendicular lines joining the point to the line opposite.

Finally... The solution...

Along the way, mathematical languages come in: For example

  • Describe a perpendicular bisector. Perpendicular bisector of a line? No, line is ofnfinite length. So, it has to be a line segment.

Indeed, I like this activity! We can incorporate more ICT use in this particular activity. Instead of providing them the map, we could actually task the students to gather the information from GoogleMap! On the other hand, more scaffold could be provided to guide the students to pen down their thoughts while they explore the various possibilities using Geogebra.

7. Why Venus is a Morning & Evening Star?

  • AU: Units of Measure Distance between the sun and a planet
  • AU> Astronomical Unit, a measure of distance, based on the mean sun-Earth distance. The International Astronomical Union defines the AU as the distance from the Sun at which a particle of negligible mass, in an unperturbed orbit, would have an orbital period of 365.2568983 days (a Gaussian year). The AU is thus defined as 1.4959787066E+11m (149,597,870.66 km). [source:]
  • Examples: Mercury 0.3871; Earth 1.000 AU
  • Distance bewteen sun and venus:

Solving the problem

  • Assumption 1: Earth, Venus and Sun lie on the same plane
  • Assumption 2: Venus and Earth rotate around the sun (in circles) as students have not learn about ellipses yet


June Holiday Projects - TLLM iGnite ProjectSecondary 3 - 2009

Other useful sites:


One of the biggest takeaway is the introduction to Geogebra! Well, compared to the version I saw last time, it's more user-friendly! Certainly, it's possible for us to use in our classrooms! Good news - it could run in both Windows and Mac platforms!

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