An exposition on the mathematics of pizza ordering

So Gier wanted pizza for late lunch. Since we are regular devourers of Domino’s, we used a discount coupon that they freely distributed. The choice was between Offer 1 (50% off on your 2nd pizza purchase) and Offer 2 (RM 45 for 3 regular pizzas).

Gier wanted 2 large pizzas, i.e. Offer 1. I asked, why not Offer 2 since you get 3 regulars instead of 2 large? And so he began:

“So we want to find out if 2 large pizzas are equal to 3 regular pizzas. The surface of a circle; i.e. our pizza is calculated by:

Area= TTr2
= TT x r x r

We know that a regular pizza is 9-inches, and a large pizza is 12-inches. For a regular pizza, its radius is 4.5 inches. 22/7 x 4.5 x 4.5 = 63.6 sq inches per regular pizza. Multiply it by 3 pizzas = 190.8 sq inches.

For a large pizza, its radius being 6 inches means 22/7 x 6 x 6 = 113.1 sq inches. Multiply it by 2 = 226.2 sq inches.

Now, anyone would know that 226.2 is bigger than 190.8! 2 large pizzas are bigger than 3 regular pizzas by 35.4 square inches!

So Domino’s is selling a thin-crust large pizza at RM 29.80. Offer 1 = RM 44.70 for 226.2 sq inches of pizza. Offer 2 is RM 45 for 190.8 sq inches of pizza. It’s less pizza and more expensive by RM 0.30! The choice is so obvious!!”

He ordered a ‘Classified Chicken’ and a ‘Beef Suspense’. They were nice. He also gave this blog post its final title.