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# Speed Math Multiplication Calculator

method: autoselect • select automatically
• multiplication by nines
• multiplication by ones
• multiplication using a base
• direct multiplication
• multiplication by drawing lines
• multiplication of equal-digit numbers when left part is common and sum of right parts is a power of ten
• multiplication of two-digit numbers when units digits are same and sum of tens digits is ten book mode
book mode
book mode
video mode

## Quick Start Guide

This calculator multiplies two numbers using speed math methods and provides step by step solutions. For example, enter 104*112 and click on 'Multiply' button.

When method is 'autoselect', most suitable method will be automatically used in accordance with the numbers. However, a particular method can be enforced by selecting that method.

Solution can be displayed with animation(video mode) or in text format (book mode).

Random examples can be generated according to selected method by clicking on 'Example' button.

## Supported Speed Math Methods

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Multiplication by nines

This method can be used to multiply any number by 99, 999, etc. It is subdivided as follows.

(a) number of digits < number of nines

examples: 56×999, 235×9999, random example

(b) number of digits = number of nines

examples: 56×99, 2356×9999, random example

(c) number of digits > number of nines

examples: 562×99, 23563×9999, random example

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Multiplication by ones

This method can be used to multiply any number by 11, 111, etc. It is subdivided as follows.

(a) number of digits < number of ones

examples: 67×111, 892×1111, random example

(b) number of digits ≥ number of ones

examples: 5626×111, 7225×1111, 7225×11, 67×11, random example

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Multiplication using a base

This method can be used to multiply two numbers when both numbers are close to a power of ten (10,100,etc., called base) or a multiple of power of 10 (called working base).

(a) numbers are close to a power of ten

examples: 102×103, 98×97, 97×103, 1007×1623, 992×997, 818×1007, random example

(b) numbers are close to a multiple of power of 10

examples: 53×54, 47×46, 46×56, 407×422, 678×692, 1823×2007, random example

+
Direct multiplication

This method can be used to multiply any two numbers.

examples: 56×78, 653×23, 762×462, random example

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Multiplication by drawing lines

This method can be used to visually multiply any two numbers. Multiplication is done by drawing lines and counting intersections. Though this method is very simple, it may become tedious with larger numbers or numbers with larger digits.

examples: 12×23, 312×21, 123×234, random example

+
Multiplication of equal-digit numbers when left part is common and sum of right parts is a power of ten

This method can be used to multiply two numbers having equal number of digits under following conditions.

• There is a common left part.
• Sum of right parts is 10,100,1000,etc.

examples:

87×83 (common left part: 8, sum of right parts: 7+3=10)

121×129 (common left part: 12, sum of right parts: 1+9=10)

102×198 (common left part: 1, sum of right parts: 02+98=100

random example

+
Multiplication of two-digit numbers when units digits are same and sum of tens digits is ten

This method can be used to multiply two two-digit numbers under following conditions.

• Units digits are same.
• Sum of tens digits is 10.

examples: 49×69, 74×34, 31×71, random example

## References

The methods used by this calculator are taken from Vedic Mathematics and other popular speed math systems.