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ISEE math · 3-minute read

One example is not always enough.

Compare quantities without guessing

An original website mini lesson · Learning On My Own

The idea

A comparison asks how two quantities relate. You need a result that is true for every value allowed by the question, not just the first value you try.

Original practice example

x is a positive number.

Quantity AQuantity B
x²x
  1. Try x = 2. Then A = 4 and B = 2. A is greater.
  2. Try x = ½. Then A = ¼ and B = ½. B is greater.

Both values are allowed. The relationship changes, so the information is not enough to decide.

Watch the word “positive”

Positive means greater than zero. It does not mean whole number. Fractions such as ½ are positive too. If the question said x > 1, then x² would always be greater than x.

Your turn

If x > 3, compare Quantity A: x + 2 with Quantity B: 5.

See the answer and reason

A is always greater. Since x > 3, adding 2 gives x + 2 > 5. The strict “greater than” matters: x cannot be 3.

This sample teaches an ISEE quantitative-comparison method. SolveTrail also covers SSAT math using the formats for that exam.

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