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GMAT Strategy

Fraction-Decimal Anchors

Recall common fraction-decimal-percent equivalents to compare values and estimate quickly.

4 min

Why memorize

Common fractions should feel like numbers, not conversion problems.

Fast recognition saves time in Quant and Data Insights when comparing rates, shares, and percentages.

Halves, thirds, and quarters

1/2
0.50 = 50%
1/3
0.333... = 33.3%
2/3
0.667... = 66.7%
1/4
0.25 = 25%
3/4
0.75 = 75%

Fifths and tenths

1/5
0.20 = 20%
2/5
0.40 = 40%
3/5
0.60 = 60%
4/5
0.80 = 80%
1/10
0.10 = 10%

Sixths and eighths

1/6
0.1667 = 16.7%
5/6
0.8333 = 83.3%
1/8
0.125 = 12.5%
3/8
0.375 = 37.5%
5/8
0.625 = 62.5%

More useful anchors

7/8
0.875 = 87.5%
1/7
about 0.1429
1/9
0.111...
1/20
0.05 = 5%
1/40
0.025 = 2.5%

Comparison

Use anchors to compare without full division.

For example, 7/15 is slightly below 1/2 because 7.5/15 would equal 1/2.

Application

Use anchors to estimate percent change or weighted data.

Recognizing 3/8 as 37.5% is faster than long division and often precise enough.

Mini application

Try this: which is larger, 5/8 or 0.61?

Use a memorized anchor before scrolling.

Solution

5/8 is larger.

5/8 = 0.625, which exceeds 0.61.

Remember this

Memorize the anchors you see repeatedly.

The goal is instant recognition of common values, not a giant conversion table.

Lesson 15 of 32

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