CAHSEE Math 3.3 Mathematical Reasoning

Mathematical Reasoning Drill 3 Problem 3. When adding these fractions without finding the lowest common denominator, which of the following is the best estimate of the exact sum?

CAHSEE MathMathematical Reasoning
LanguageEnglish Language
MathAlgebra
Mathematical ReasoningEstimating unknown quantities

Transcript

00:27

Basically, we just have to look at each of

00:29

the fractions and come up with a rough estimate for how close they are to 1/9, 1/3, ½ or 2/3.

00:37

3.5 sevenths would be a half, so 3 sevenths is slightly under.

00:42

4.5 ninths would be a half, so 5 ninths is slightly over.

00:49

Anyway. You get the idea.

00:51

The answer is a bunch of halves… or C.