CQ
CAT QuantsDaily Challenge

📚 My Tricks

Your personal collection of quantitative shortcuts and techniques

4
Total Tricks
2
Favorites
65
Times Used
4.7
Avg Rating
Categories
Browse tricks by category

Mental Math

12 tricks

Approximation

8 tricks

Number Theory

6 tricks

Algebra

10 tricks

Geometry

5 tricks
Square of Numbers Ending in 5
Quick method to calculate squares of numbers ending in 5
Mental Math
Easy

Steps:

  1. Take the number without the 5 (e.g., for 25, take 2)
  2. Multiply it by the next number (2 × 3 = 6)
  3. Append 25 to the result (625)

Example:

25² = 2 × 3 = 6, append 25 → 625

Used 15 times
4.8
squares
mental-math
quick-calculation
Percentage Shortcuts
Fast ways to calculate common percentages
Approximation
Medium

Steps:

  1. 10% = Move decimal one place left
  2. 5% = Half of 10%
  3. 15% = 10% + 5%
  4. 20% = 2 × 10%

Example:

15% of 80 = 10% (8) + 5% (4) = 12

Used 23 times
4.6
percentage
approximation
shortcuts
Divisibility by 11
Quick test to check if a number is divisible by 11
Number Theory
Medium

Steps:

  1. Add digits in odd positions
  2. Add digits in even positions
  3. Find the difference
  4. If difference is 0 or divisible by 11, the number is divisible by 11

Example:

121: (1+1) - (2) = 0, so 121 is divisible by 11

Used 8 times
4.4
divisibility
number-theory
quick-test
Multiplication by 11
Fast method to multiply any 2-digit number by 11
Mental Math
Easy

Steps:

  1. Write the first digit
  2. Add the two digits and write in middle
  3. Write the last digit
  4. If sum > 9, carry over to the left

Example:

23 × 11 = 2(2+3)3 = 253

Used 19 times
4.9
multiplication
mental-math
shortcuts