Vedic Maths Sutra 03 : Ūrdhva-Tiryagbhyām
Meaning & Essence
This Sūtra means “Vertically and Crosswise”. It is the most general and powerful multiplication technique in Vedic Mathematics. Unlike the previous two Sūtras which work best for special cases, this method works for any two numbers of any size.
The method multiplies digits vertically and then crosswise, making it ideal for mental calculation once you get used to the pattern. It can be extended from 2-digit numbers to 3-digit, 4-digit and beyond.
Mathematical Principle
For two 2-digit numbers written as \( 10a + b \) and \( 10c + d \):
For three-digit numbers the same idea expands:
In simple words (working from right to left):
- Vertical on the units place
- Crosswise on successive groups of digits
- Continue moving left, combining vertical and crosswise products
- Handle carries whenever a result has more than one digit
Worked Examples
- Units (vertical): \( 3 \times 2 = 6 \)
- Crosswise: \( 2 \times 2 + 3 \times 1 = 4 + 3 = 7 \)
- Tens (vertical): \( 2 \times 1 = 2 \)
- Units: \( 8 \times 7 = 56 \) → write 6, carry 5
- Crosswise: \( 4 \times 7 + 8 \times 3 = 28 + 24 = 52 \) + carry 5 = 57 → write 7, carry 5
- Tens: \( 4 \times 3 = 12 \) + carry 5 = 17
- Units: \( 3 \times 6 = 18 \) → write 8, carry 1
- Tens cross: \( 2 \times 6 + 3 \times 5 = 12 + 15 = 27 \) + 1 = 28 → write 8, carry 2
- Hundreds: \( 1 \times 6 + 2 \times 5 + 3 \times 4 = 6 + 10 + 12 = 28 \) + 2 = 30 → write 0, carry 3
- Thousands: \( 1 \times 5 + 2 \times 4 = 5 + 8 = 13 \) + 3 = 16 → write 6, carry 1
- Ten-thousands: \( 1 \times 4 = 4 \) + 1 = 5
When to Use This Sūtra
• Multiplication of any two numbers (2-digit, 3-digit, 4-digit and larger)
• Especially powerful for mental math with 2-digit and 3-digit numbers
• Can also be extended to algebraic multiplication and division
• The most versatile multiplication method in Vedic Mathematics