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a recipe calls for a total of 3 2/3 cups of flour and sugar. it the recipe calls for 1/4 cup of sugar, how much flour is needed?

User RankWeis
by
5.4k points

1 Answer

1 vote

Answer:

This is very detailed as I wish to make some principles about fractions clear.

3

5

12

Explanation:

This question boils down to

3

2

3

1

4

A fractions structure is that of:

count

size indicator of what you are counting

numerator

denominator

You can not directly add or subtract the counts (numerators) unless the size indicators (denominators) are the same.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Consider

3

2

3

Write as

3

+

2

3

Multiply by 1 and you do not change the value. However, 1 comes in many forms so you can change the way something looks without changing its true value

[

3

×

1

]

+

2

3

[

3

×

3

3

]

+

2

3

9

3

+

2

3

=

11

3

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Putting it all together

3

2

3

1

4

11

3

1

4

But the size indicators are not the same. I chose to make them become 12

11

3

1

4

[

11

3

×

1

]

[

1

4

×

1

]

[

11

3

×

4

4

]

[

1

4

×

3

3

]

44

12

3

12

Now we may subtract the counts

44

3

12

=

41

12

But this is the same as

12

12

+

12

12

+

12

12

+

5

12

=

1

2

+

2

1

2

+

2

1

2

+

5

12

=

3

5

12


Explanation:


User Loresa
by
4.9k points