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The 99% Trick

99% of a number is just the number minus 1% of it.

When to use

Any problem asking for 99% of something.

Steps

  1. 1.Find 1% of the number (divide by 100)
  2. 2.Subtract from the original number

Example: 99% of 443

1% of 443 = 4.43

443 - 4.43 = 438.57

Mental approach

99% of 443 → 443 minus 4.43 → 438.57. Just move the decimal two places left and subtract.

Pen & paper approach

Write the number, write 1% below, subtract.

Tips

  • •This generalizes: 98% = number - 2%, 95% = number - 5%
  • •For whole numbers: 99% of 300 = 300 - 3 = 297

Try it yourself

99% of 250

99% of 680

99% of 1,000