Bits and Pieces III Investigation 3.1 The Decimal Divide

Bits and Pieces IIIBits and Pieces IIIInvestigation 3.1

The Decimal Divide

You will be able to:You will be able to:

GOALS

Choose between division, multiplication, addition, or subtraction as an appropriate operation to use to solve a problem.

Use models and the context to find solutions to division problems

Estimate to find approximate solutions

In a grocery store, all of the scales measure in decimals. Explain or draw diagrams to show your reasoning for the following situations.

Ricardo buys 3.2 ounces of a slice Italian ham called prosciutto to make sandwiches. Each sandwich uses one 0.4-ounce slice of prosciutto. How many sandwiches can he make?

What does the 3.2 and the o.4 in Question A part(1) represent?


What does the 3.2 and the o.4 in Question A

part(1) represent?


3.2 represents the total ounces of prosciutto Ricardo bought and o.4 is how many ounces goes on a sandwich.

Write a number sentence solving this problem.


Ricardo buys 3.2 ounces of a slice Italian ham called prosciutto to make sandwiches. Each sandwich uses one 0.4-ounce slice of prosciutto. How many sandwiches can he make?Number sentence: 3.2 divided by 0.4 = 8

sandwiches

This is done by making decimal numbers into whole numbers just like multiplication.32 divided by 4 = 8 sandwiches this is the same mathematically as 3.2 divided by 0.4 = 8 sandwiches

Ms. Difanis buys 11.6 pounds of hamburger for a cookout. How many quarter-pound (0.25) burgers can she make?


What does the 11.6 and the 0.25 in Question A part(2) represent?


What does the 11.6 and the 0.25 in Question A

part(2) represent? 11.6 represents the pounds of hamburger she has0.25 represents how much hamburger each individual patty or quarter pounder contains


Write a number sentence solving the problem.

Ms. Difanis buys 11.6 pounds of hamburger for a cookout. How many quarter-pound (0.25) burgers can she make? 11.6 and 0.25, since 0.25 has two numbers to

the right of the decimal than 11.6 has to have two numbers to the right of the decimal. THEN-1160 divided by 25 = 46.4 quarter-pound hamburgers

NOTE: This is not the same as multiplying decimals. You must move the decimal over the same number of times in each factor.

11.6 divided by 0.25 = 46.4

What does the 0.4 in 46.4 represent?

11.6 divided by 0.25 = 46.4 What does the 0.4 in 46.4 represent?

There are 46 quarters in 11.6 and o.4 left over, which means you can make 0.4 of another patty.

Why is division appropriate for these problems?

Why is division appropriate for these problems?

There is quantity that is being divided into parts of equal size.

Are the division situations in A(1) and A(2) sharing or grouping ?

Are the division situations in A(1) and A(2) sharing or grouping ?

These are sharing problems. For the first problem you find 0.4 slices you can get from 3.2 ouncesandfor the second problem you find 0.25 pattys you can make from 11.6 lbs of burger

Ashley eats five 5.25 ounce slices of watermelon in a contest at the the picnic. How many ounces of watermelon does she eat?


What operation do you use here? Estimate your answer.



You use multiplicationEstimate 5 x 5 = 25

Stacey needs $39.99 for a pair of sneakers. She has $22.53 in her savings and a $15 check from babysitting. Can she buy the shoes?





First add $23.00 and $15 to get $38, so then since $38 is less than $40. We can say she does not have enough money to buy the sneakers.

Li Ming’s allowance for transportation is $12.45. How many times can she ride the bus if it costs $0.75 a trip?


Li Ming’s allowance for transportation is $12.45. How many times can she ride the bus if it costs $0.75 a trip?


You would use division here$12 divided by $1 = 12 rides 0ryou could say multiplication since 0.75 + 0.75 = 1.50 + 1.50 =3 dollars = 4 trips then you could say 4 times what number is 12 the answer is 3 thus 4x3=12.

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Bits and Pieces III Investigation 3.1 The Decimal Divide