Question 2 - Loose and Pre-packaged Almonds Problem

Daily Life Activity: Loose and Pre-packaged Almonds Problem

2-Loose almonds in a supermarket cost $6.48 for 250 gm, or you can buy 375 gm of pre-packaged almonds for $10.65. Which is the better buy? How might you calculate this in a shop?

Solution:

PART 1- Decision Making - In general, a cheaper price should be the better buy.

*Method 1

Currently in Australia, in supermarkets such as Woolworths and Coles, in order to provide information of food products to customers, the price units, for example costs per 100 gm, are already calculated. I only need to check those before my decision making.

*Method 2 
My full explanation:
I would bring with me a pocket calculator such as my Iphone, to find out the price per 100 grams as below.
- the cost per 100 grams [the cost unit] of loose almonds = ($6.48 ÷ 250 gm) x 100 = $2.59 per 100 gm

- the cost per 100 grams of pre-packaged almond = ($10.65 ÷ 375 gm) x 100 = $2.84 per 100 gm

Practicing with my calculator - Press chosen numbers and relevant functions to find 
-the cost unit of loose almonds                ==>               6.48 ÷ 250 x 100 = 2.59
-the cost unit of pre-packaged almonds ==>             10.65 ÷ 375 x 100 = 2.84


The results show the cost per 100gm of loose almonds of $2.59 is the cheaper price.
Therefore, a choice of loose almonds will be the better buy.

*Method 3
Having no calculators, I would create or set my own 'common measureable unit', for example, in this case I would double 375 gm of pre-packaged almonds to make it  becomes 750 gm; and then I need triple 250gm of loose almonds to make it becomes 750 gm. Now I have them in the same my 'common measureable unit' of 750 gm.
Then working in my head, the double price of 750 gm of pre-package almonds is the double of $10.65 that equals something more than $20 - I just need to know roughly this figure [the exact figure is $21.30]; and the triple price of loose almonds is the triple of $6.48 that equals something less than $20 - and again, I only need to know roughly this figure [the exact figure is $19.44]. 

Therefore, a choice of loose almonds would be the better buy in my head.

*Further in reality, in many cases, if buying a small amount of almonds, for example I need to buy 100 gm only - i.e. an amount is less than 375 gm,  or an even amount for example one kilogram, then buying loose almonds would be my first choice. This choice would be made without any thinking and calculations. 
Therefore, in these situations, I would go straight to buy the loose almonds without making any comparisons of prices.

My notes

*Why do the loose almonds and pre-packaged almonds matter? 

*Why do I need to know this matter?

*For viewers: You may have more different methods or options depending on your own choices, contexts, and other factors.

PART 2 - PEERS' FEEDBACK

With more detailed information, this task can also be viewed @ 
*my google site Learning Teaching Adult Numeracy in VET at https://sites.google.com/site/lydiale2016eeb308csu/which-is-the-better-buy;