Transcript How Much Dog Food? - University of Texas at Austin

How Much Dog Food?
By Victoria Kin
TEKS
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(4.2) Number, operation, and quantitative reasoning. The student describes
and compares fractional parts of whole objects or sets of objects. The student
is expected to:
(A) use concrete objects and pictorial models to generate equivalent
fractions.
(4.3) Number, operation, and quantitative reasoning. The student adds and
subtracts to solve meaningful problems involving whole numbers and
decimals. The student is expected to:
(A) use addition and subtraction to solve problems involving whole numbers.
(4.4) Number, operation, and quantitative reasoning. The student multiplies
and divides to solve meaningful problems involving whole numbers. The
student is expected to:
(D) use multiplication to solve problems (no more than two digits times two
digits without technology);
(E) use division to solve problems (no more than one-digit divisors and threedigit dividends without technology).
(4.11) Measurement. The student applies measurement concepts. The student
is expected to estimate and measure to solve problems involving length
(including perimeter) and area. The student uses measurement tools to
measure capacity/volume and weight/mass. The student is expected to:
(B) perform simple conversions between different units of length, between
different units of capacity, and between different units of weight within the
customary measurement system.
 It’s time for
BK’s dinner.
Uh-oh!
Looks like we
need to get
more dog
food for BK.
At the pet store….
 BK’s dog food comes in three sizes: 5-
pound, 17-pound, and 35-pound bag.
 The 17-pound and 35-pound bags are
too big and heavy to carry.
 I wonder how
much dog food
BK eats in a
month. Will a 5
pound bag of
dog food last for
a month?
Let’s gather some facts…
 BK eats 1/4 cup of food each meal.
 She eats twice a day.
 There are 30 days in November.
 1 cup = 8 ounces
 16 ounces = 1 pound
How much food does BK eat in a
month?
 BK eats 1/4 cup of
food each meal,
and she eats twice
a day. 2 x 1/4 cup
= 1/2 cup, which
means she eats 1/2
cup a day.
 1/2 cup x 30 days =
15 cups per month.
How many pounds are 15 cups?
 First, I need to find out how many ounces
15 cups are. 1 cup = 8 ounces, this
means
15 x 8 ounces = 120 ounces.
 Since it takes 16 ounces to convert into 1
pound, then 120 ounces must be divided
by 16
120 ounces  16 = 7.5.
 BK eats 7.5 pounds of food each month.
Will a 5-pound bag be enough for
1 month?
 A 5-pound bag is not enough for BK,
because she eats 7.5 pounds of
food for a month.
 7.5 - 5 = 2.5
 This means BK need 2.5 pounds of
food in addition to the 5-pound
bag.
BK needs more dog food!
 If I need the food to last at least a month,
I will have to buy the larger bag of dog
food for her.