Question

Describe the process you would use to find the solution to the problem 3 1/4 minus1 1/3. Express your answer numerically and with a graphical representation.

Answer 1

3 1/4 - 1 1/3=
3 3/12 - 1 4/12=
2 15/12 - 1 4/12=
1 11/12

Answer 2

1 11/12

Explanation:

Notice (right away) that the denominators of the fractions are different (4 and 3).

Identify the LCD: It is 12.

Convert the two given numbers to mixed numbers with LCD 12:

3 3/12

-1 4/12

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4/12 is greater in magnitude than 3/12, so we must 'borrow' from the digits' place. Recall that 1 = 12/12.

Then 3 3/12 = 2 15/12. -1 4/12 stays the same; it has LCD 12.

Then, perform the indicated subtraction:

2 15/12

-1 4/12

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1 11/12 (answer: this is the difference "3 1/4 less 1 1/3")