SPEED MATH & VEDIC TRICKS VAULT ✦ CUBE ROOTS IN 5 SECONDS ✦ TRIPLETS CHEAT SHEET ✦ NO MATH ANXIETY ✦ SPEED MATH & VEDIC TRICKS VAULT ✦
Speed Calculation Foundation

Speed Math & Vedic Tricks

Master Cube roots in 5 seconds, mental multiplication, squares up to 50, and Pythagorean Triplets chart.

The Bodhi Vault / Quant Vault / Speed Math
DEFINITION

One-Line Definition

Speed Math comprises mental calculation shortcuts, Vedic math algorithms, and pattern recognition designed to eliminate long division and manual multiplication during competitive exams.

Goal: Save 15-20 minutes in non-calculator exam sections!
CORE INTUITION ⚡

Rapid Pattern Engine Model

Multiply 96 × 94 without long multiplication:

  • • Deviations from 100: -4 and -6
  • • Cross subtract: 96 - 6 = 90 (First 2 digits)
  • • Multiply deviations: (-4) × (-6) = 24 (Last 2 digits) → Result = 9024!
Mental shortcuts turn 30-second multiplications into 2-second visual checks.
💡 WHY THIS CONCEPT MATTERS IN MBA EXAMS

Speed math is crucial for high-velocity exams like MBA CET (200 questions in 150 mins), NMAT, SNAP, and CAT Data Interpretation:

MBA CET 200-Q Drills
NMAT 1-Min Questions
SNAP Rapid Fire
DI Calculation Speed
Instant Cube Roots
Digital Root Eliminator
Pythagorean Triplets
Ending in 5 Squares
⚡ PYTHAGOREAN TRIPLETS CHEAT SHEET
Primary

3 - 4 - 5

Multiples: 6-8-10, 9-12-15, 12-16-20, 15-20-25

Primary

5 - 12 - 13

Multiples: 10-24-26, 15-36-39, 20-48-52

Primary

7 - 24 - 25

Multiples: 14-48-50, 21-72-75

Primary

8 - 15 - 17

Multiples: 16-30-34, 24-45-51

Squaring Numbers Ending in 5 Rule:

(N5)² = [ N × (N + 1) ] | 25

Example: 35² → 3 × 4 = 12 → 1225. 65² → 6 × 7 = 42 → 4225.

SHORTCUT RULES & KEY FORMULAS

5-SECOND SHORTCUT

Instant Cube Root in 5 Seconds

Unit Digits: 1,4,5,6,9,0 remain SAME | 2 ↔ 8 and 3 ↔ 7 SWAP

Strike off the last 3 digits. Find the largest cube less than or equal to the remaining number.

⚡ Mental Shortcut: ∛17576 → Ends in 6 (Unit digit = 6). Strike 576. Remaining 17 is between 2³=8 and 3³=27 → First digit = 2 → Result = 26!
VEDIC MULTIPLICATION

Base 100 Multiplication Trick

(100 - a) × (100 - b) = [100 - (a + b)] | (a × b)

Calculates multiplication of numbers close to 100 in under 3 seconds.

⚡ Mental Shortcut: 98 × 97 → Deviations -2 and -3 → First digits = 98 - 3 = 95 → Last digits = (-2)×(-3) = 06 → Result = 9506.

SOLVED EXAMPLES (LEVEL 0 TO HARD)

Example 1 (Easy / Ending in 5 Square)

Q: Find the square of 35 mentally using the ending in 5 rule.

Step 1: Tens digit N = 3 → Multiply N × (N + 1) = 3 × 4 = 12.

Step 2: Append 25 at the end → Result = 1225.

Answer = 1225
Example 2 (Medium / Base 100 Multiplication)

Q: Multiply 96 × 94 using the Base 100 Vedic shortcut.

Step 1: Deviations from 100: 96 is -4, 94 is -6.

Step 2: Left part = 96 - 6 = 90 (or 94 - 4 = 90).

Step 3: Right part = (-4) × (-6) = 24 → Combine = 9024.

Answer = 9024
Example 3 (Hard / Instant Cube Root)

Q: Find the cube root of 17576 in 5 seconds.

Step 1: Last digit of 17576 is 6 → Unit digit of cube root = 6.

Step 2: Strike off last 3 digits (576) → Remaining number = 17.

Step 3: Largest perfect cube ≤ 17 is 8 (2³) → Tens digit = 2 → Result = 26.

Answer = 26
⚠️ COMMON MISTAKES TO AVOID IN CAT & CET

Mistake 1

Unit Digit Swap Confusion

Forgetting that 2 swaps with 8 and 3 swaps with 7 in cube roots (all other digits 1, 4, 5, 6, 9, 0 stay unchanged!).

Mistake 2

Forgetting Base 100 Leading Zero

When multiplying 98 × 99 (deviations -2 and -1), product is 2. Must write as two digits: 02 → Result 9702 (NOT 972).

Mistake 3

Misapplying Digital Root on Division

Using digital root directly on division without converting to multiplication. Digital root works seamlessly on +, -, × only.

📝 PRACTICE QUESTIONS
Basic

1. Calculate 45² mentally using ending in 5 rule.

Answer: 4 × 5 = 20 → Append 25 = 2025.

Moderate

2. Multiply 98 × 97 using Base 100 Vedic trick.

Answer: Deviations -2 and -3 → Left: 98-3 = 95. Right: (-2)×(-3) = 06 → 9506.

Advanced

3. Find ∛110592 mentally in 5 seconds.

Answer: Last digit 2 → Unit digit 8. Remaining 110 is between 4³=64 and 5³=125 → Tens digit 4 → Result = 48.

FREQUENTLY ASKED QUESTIONS

❓ How do you find the cube root of any perfect cube in 5 seconds?

Look at the last digit: 1,4,5,6,9,0 remain the same. 2↔8 and 3↔7 swap. Strike off the last 3 digits, and find the largest cube less than or equal to the remaining number for the tens digit.

❓ How does the ending in 5 squaring rule work?

For any number ending in 5 (e.g. N5), multiply the tens digit N by (N + 1) and append 25 at the end. For 35: 3 × 4 = 12 → 1225.

❓ What is Digital Root checking for option elimination?

Digital root is the single-digit sum of all digits in a number. The digital root of the question expression must equal the digital root of the correct answer option.