Answers to Pg. 203-206 # 1, 2 (not f), 3 (not b), 4 (not a):
1) The big box of butter cubes looks like it contains more. It appear to be larger because they have
spread the butter out over a larger package even though both of them have the same net weight of
454 g.
The box of potato chips looks like it contains more than the can of chips. The same net weight of chips
200 g is in each container there would just be more empty space in the box of chips.
2)
a) Cereal # 1 = Whole Wheat, Cereal #2 = Flaked milled corn
b) Cereal # 1 = 30 g = 160 mL (2/3 cup) , Cereal #2 = 30 g = 300 mL (1 ¼ cup)
c) Cereal # 1 = 110 Cal or 460 kJ, Cereal #2 = 112 Cal or 470 kJ
Cereal #2 contains more energy per
serving
d) Cereal # 1 Iron = 29% per serving
e) Cereal # 2 Vitamin B6 = 10 % per serving
# 𝑠𝑒𝑟𝑣𝑖𝑛𝑔𝑠 𝑛𝑒𝑒𝑑𝑒𝑑 𝑓𝑜𝑟 𝑑𝑎𝑦 =
100 %
% 𝑝𝑒𝑟 𝑠𝑒𝑟𝑣𝑖𝑛𝑔
= 100 % ÷ 10 % = 10 servings needed to meet
recommended daily intake
3)
a) Tuna contains more protein
c) 1 serving size = 50 g
d) The net weight = 170 g and the drained weight = 120 g
e) # 𝑠𝑒𝑟𝑣𝑖𝑛𝑔𝑠 =
𝑡𝑜𝑡𝑎𝑙 𝑤𝑒𝑖𝑔ℎ𝑡 𝑖𝑛 𝑝𝑎𝑐𝑘𝑎𝑔𝑒
𝑤𝑒𝑖𝑔ℎ𝑡 𝑝𝑒𝑟 𝑠𝑒𝑟𝑣𝑖𝑛𝑔
= 120 g ÷ 50 g = 2.4 servings of tuna per can
f) I used the drained weight
4)
b) Peanut butter contains more fat
c) 2 tablespoons per serving
d) 1.5 kg = 1500 g
# 𝑠𝑒𝑟𝑣𝑖𝑛𝑔𝑠 =
𝑡𝑜𝑡𝑎𝑙 𝑤𝑒𝑖𝑔ℎ𝑡 𝑖𝑛 𝑝𝑎𝑐𝑘𝑎𝑔𝑒
𝑤𝑒𝑖𝑔ℎ𝑡 𝑝𝑒𝑟 𝑠𝑒𝑟𝑣𝑖𝑛𝑔
= 1500 g ÷ 32 g = 46.9 servings
e) There is 8.4 g of protein in each serving of peanut butter.
Math 431 Lesson plan: Exploration #2
“The Cost of One”
pg. 210 – 214
The Cost of One:
- When you buy a package of a food there are usually multiple servings in one package.
Ex. 12 pack of pepsi has 12 servings per package
- You can get different size packages of the same product, each package will cost a different amount
Ex. Can buy a 1 litre container of milk or a 2 litre container of milk.
- On price labels you will find a cost per unit written on it.
Ex. Bag of Chips = 240 g Price label may have a value reading $1.25/100g
- You would then compare these unit prices between different size packages and brands to find the best deal
Ex. Lays BBQ unit price = $1.04/100g
Doritos BBQ unit price = $1.25/100g
Unit Price: the cost of one unit of a product shown as cost per unit
𝑈𝑛𝑖𝑡 𝑝𝑟𝑖𝑐𝑒 =
𝐶𝑜𝑠𝑡 𝑜𝑓 𝑝𝑎𝑐𝑘𝑎𝑔𝑒
# 𝑜𝑓 𝑢𝑛𝑖𝑡𝑠 𝑖𝑛 𝑎 𝑝𝑎𝑐𝑘𝑎𝑔𝑒
Ex 1). 12 pack bottle of water costs $3.75, a unit in this case will be one bottle of water.
𝑈𝑛𝑖𝑡 𝑝𝑟𝑖𝑐𝑒 =
$3.75
= $0.31/𝑏𝑜𝑡𝑡𝑙𝑒
12 𝑏𝑜𝑡𝑡𝑙𝑒𝑠
Ex. 2) You are at Sobeys and notice that the 6-pack of Gatorade is on sale for $4.99. What is the unit price if a
unit is a bottle.
Which is the better price per unit ?
To compare the unit price of two items;
- both prices have to be in the same unit
Ex. $/unit compared to $/unit can’t have $/unit compared to ¢/unit
- both quantities mush be in the same unit
Ex. $/mL compared to $/mL
can’t have $/mL compared to $/L
Ex 1) Jennifer wants to buy some orange juice. The orange juice comes in two sizes. The smaller size sells at
99¢ for 355 mL while the larger size sells at $1.19 for 500 mL. Which is the better buy?
Example problems:
1. A bag of Uncle Ben’s bread costs $1.69/loaf, if each bag of bread has 20 slices of bread what is the unit
price?
$𝟏. 𝟔𝟗 ÷ 𝟐𝟎 𝒔𝒍𝒊𝒄𝒆𝒔 = $𝟎. 𝟎𝟖 𝒑𝒆𝒓 𝒔𝒍𝒊𝒄𝒆
If you were to make a sandwich how much would it cost you for the bread?
𝟐 𝒔𝒍𝒊𝒄𝒆𝒔 × $𝟎. 𝟎𝟖 𝒑𝒆𝒓 𝒔𝒍𝒊𝒄𝒆 = $𝟎. 𝟏𝟔
2. You find a box of cookies on sale for $3.99 with a net weight of 960 g. If each unit is 30 g;
a) How many servings are there in total?
b) What is the unit price?
c) If you and your friends eat 4 servings how much would that cost?
3. You are out grocery shopping and are out to pick up cereal. You find a box of Cheerios that has 525 g and
costs $4.89, and a larger box of Cheerios that had 830 g and costs $7.49. Which is the better deal per 100 g?
a) How many 100g servings in each box?
b) What is the unit price (1 unit = 100 g) of each box of cereal?
4. You feel like buying yourself a treat of chocolate milk. You walk down the dairy aisle, find the chocolate
milk, and notice that you can purchase it in a variety of sizes. The carton # 1 contains 500 mL and costs $1.49,
carton # 2 contains 1 Litre and costs $2.48.
a) If the unit price is per mL what is the unit price value for carton #1 and carton #2?
b) If the unit price per 100 mL how many units are in carton #1 and in carton #2?
c) What is the unit price per 100 mL in carton #1 and in carton #2, which is the better deal?