Arithmetic Grade Five

Lesson One Hundred and Twenty: Averages of Mixed Numbers

Finding the average of a group of mixed numbers is like finding the average of a group of fractions. 


	FRACTIONS: 2 2/3, 1 3/5, 1 1/3, 1 2/5, 2 1/4.

	STEP ONE: Add the mixed.

		2 2/3 + 1 3/5 + 1 1/3 + 1 2/5 + 2 1/4 =

		Find least common denominator: 60

		Convert fractions:

		  2 40/60 + 1 36/60 + 1 20/60 + 1 24/60 + 2 15/60 =

		Add mixed numbers:

		  7 135/60

		Get rid of whole number:

		  7 x 60 = 420,
		  420 + 135 = 555
		  RESULT: 555/60

	STEP TWO: Divide by number of values.

		555/60 ÷ 5 =		(original problem)

		555/60 * 1/5 =		(flip and convert operator)

		111/60 =		(reduce)

		1 51/60			(convert to mixed)
Actually that's a lot of steps, but none of the steps is new.

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