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## [Speed Math] MULTIPLYING WITH 11

Here’s an example of a SPEED MATH shortcut for MULTIPLYING WITH 11 : (Mul) Nx11 from the MULTIPLICATION category. ### When can I use this method?

For multiplying any number with 11.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQfvCT75AepjIPtqaEBpZ_D4″] Download Practice sheet for  MULTIPLYING WITH 11

### Notes –

1. There is no real need to add the zero if you can remember to perform same steps for all the digits of the number (including the first and the last).
2. Make sure to take care of the carryovers as you add the neighboring digits.

### Related Shortcuts –

Multiplying with 6: (Mul) Nx6

Multiplying with 7: (Mul) Nx7

Multiplying with 12: (Mul) Nx12

Multiplying with 13: (Mul) Nx13

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Categories

## [Speed Math] MULTIPLYING NUMBERS WITH COMMON LAST DIGITS

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS WITH COMMON LAST DIGITS : (Mul) LDSdx from the MULTIPLICATION category. ### When can I use this method?

For multiplying any 2-digit number with another 2-digit number such that the last digit of the multiplier and multiplicand are same. The first digits can be different.

For multiplying any 3-digit number with another 3-digit number such that the last digit of the multiplier and multiplicand are same. The initial 2 digits can be different.

You can also use this method to multiply numbers with unequal number of digits, i.e. multiplying a 2-digit number with a 3-digit number such that the last digit of the multiplier and multiplicand are the same.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQdTM04iGzwvretUN9TGEACL”] Download Practice sheet for   MULTIPLYING NUMBERS WITH COMMON LAST DIGITS

### Notes –

1. Notice the way the products are added.

### Related Shortcuts –

Multiplying Numbers with Common Initial digits: (Mul) FDSdx

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Categories

## [Speed Math] MULTIPLYING NUMBERS USING ALIQUOT METHOD

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS USING ALIQUOT METHOD : (Mul) NxM(Aq)
from the MULTIPLICATION category. ### When can I use this method?

For multiplying any two numbers provided at least one of them can be converted to an Aliquot format.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQdAhzAASVhK7mbHsQB5bhWC”] Download Practice sheet for MULTIPLYING NUMBERS USING ALIQUOT METHOD

### Notes –

1. An aliquot of an integer is any of its integer proper divisors.
2. As you convert the numbers to its aliquot, make sure to take care of the zeros and the decimal points.

### Related Shortcuts –

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Categories

## [Speed Math] MULTIPLYING A NUMBER ENDING WITH 1

Here’s an example of a SPEED MATH shortcut for MULTIPLYING A NUMBER ENDING WITH 1:(Mul) NxM(LD1) from the MULTIPLICATION category. ### When can I use this method?

Although this can be used for multiplying any number with another number whose last digit is = 1, it is better suited for 2 or 3-digit numbers. Larger numbers could get increasingly difficult to multiply with this method.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQdVV5jt37H9ULHc355huldR”] Download Practice sheet for MULTIPLYING A NUMBER ENDING WITH 1

### Notes –

1. This method uses the concept a x (b+1) = ab + a

### Related Shortcuts –

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Categories

## [Speed Math] MULTIPLYING NUMBERS WITH LAST DIGIT SUM 10

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS WITH LAST DIGIT SUM 10: (Mul) S10dx from the MULTIPLICATION category. ### When can I use this method?

For multiplying any 2-digit number with another 2-digit number such that the sum of the last digits of the multiplier and multiplicand = 10 and the remaining digits of multiplier are same as that of the multiplicand.

For multiplying any 3-digit number with another 3-digit number such that the sum of the last digits of the multiplier and multiplicand = 10 and the remaining digits of multiplier are same as that of the multiplicand.

You cannot use this method to multiply numbers with unequal number of digits, i.e. multiplying a 2-digit number with a 3-digit number.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQfHggb5kk9PCAMBPg5AlTWh”] Download Practice sheet for MULTIPLYING NUMBERS WITH LAST DIGIT SUM 10

### Notes –

1. The RHS of the answer should always be written in 2-digit form by prefixing a zero, if the value is single digit, e.g. write ‘9’ as ‘09’.

### Related Shortcuts –

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Categories

## [Speed Math] MULTIPLYING NUMBERS NEAR 10

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS NEAR 10 : (Mul) Nr10 from the MULTIPLICATION category. ### When can I use this method?

For multiplying numbers near 10. The numbers can be either more than 10 or less than 10 or a combination of the two.

You may also use this method to multiply numbers a little farther away from 10 as long as their differences from 10 are easy to multiply.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQd5pOvUfauq-uo9aOc_puE8″] Download Practice sheet for MULTIPLYING NUMBERS NEAR 10

### Notes –

1. This method uses the concept (10 + a) (10 + b) = [(10 + a) + b] + ab or [(10 + b) + a] + ab, where ‘(10 + a)’ and ‘(10 + b)’ are numbers near 10 and ‘a’ and ‘b’ are the respective differences.
2. Whenever the number is more than 10, the difference is written as positive (+ve).
3. Whenever the number is less than 10, the difference is written as negative (-ve).
4. When both numbers are either less or more than 10, you add the product of differences.
5. When one number is more than 10 and another less than 10, you subtract the product of differences.

### Related Shortcuts –

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## [Speed Math] MULTIPLYING NUMBERS WITH LAST DIGIT SUM 1000

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS WITH LAST DIGIT SUM 1000: (Mul) S1000dx from the MULTIPLICATION category. ### When can I use this method?

For multiplying any 4-digit number with another 4-digit number such that the sum of the last 3 digits of the multiplier and multiplicand = 1000 and the remaining digits of multiplier are same as that of the multiplicand.

For multiplying any 5-digit number with another 5-digit number such that the sum of the last 3 digits of the multiplier and multiplicand = 1000 and the remaining digits of multiplier are same as that of the multiplicand.

You cannot use this method to multiply numbers with unequal number of digits, i.e. multiplying a 4-digit number with a 5-digit number.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQebf9zGUiPNA_7M7T3BOYC-“] Download Practice sheet for MULTIPLYING NUMBERS WITH LAST DIGIT SUM 1000

### Notes –

1. The RHS of the answer should always be written in 6-digit form by prefixing zero(s), if the value is less than 4-digit, e.g. write ‘9’ as ‘000009’ or ’21 as ‘000021’ or ‘121’ as ‘000121’ and so on…

### Related Shortcuts –

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Categories

## [Speed Math] MULTIPLYING NUMBERS USING LINE INTERSECTION

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS USING LINE INTERSECTION: (Mul) NxMy(Li)
from the MULTIPLICATION category. ### When can I use this method?

For multiplying any number with any other number.

Ideally, the numbers should have digits of value less than 5. This, although not a restriction, but is helpful to draw out the lines clearly and count the intersection points properly.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQciwxmy7vnNFxIfPNhXfu-C”] Download Practice sheet for MULTIPLYING NUMBERS USING LINE INTERSECTION

### Notes –

1. This is one of the most generic methods of multiplication.
2. As you would notice that it is not really a shortcut method, but just an alternative method of multiplication.

### Related Shortcuts –

Multiplying Numbers using Grid Method: (Mul) NxMy(Gd)

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## [Speed Math] MULTIPLYING NUMBERS ENDING IN 5

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS ENDING IN 5 : (Mul) LD5 from the MULTIPLICATION category. ### When can I use this method?

For multiplying any 2-digit number with another 2-digit number such that the last digit of the multiplier and multiplicand is = 5. The first digits can be different.

For multiplying any 3-digit number with another 3-digit number such that the last digit of the multiplier and multiplicand is = 5. The initial 2 digits can be different.

You can also use this method to multiply numbers with unequal number of digits, i.e. multiplying a 2-digit number with a 3-digit number such that the last digit of the multiplier and multiplicand is = 5.

As long as finding the product of initial digits is easy enough, one can use this method to multiply numbers bigger than 2 or 3-digits.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQdcEvw3BonAvcgRGtR2mhlk”] Download Practice sheet for MULTIPLYING NUMBERS ENDING IN 5

### Notes –

1. When the average of the initial digits is an integer, the last 2 digits of the answer is = 25.
2. When the average of the initial digits is in decimal, the last 2 digits of the answer is = 75.
3. If the average of the initial digits is an integer, simply appending 25 to the sum of product and average of the initial digits gives you the answer.

### Related Shortcuts –

“None”

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Categories

## [Speed Math] MULTIPLYING NUMBERS WITH FIRST DIGITS SUM 10

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS WITH FIRST DIGITS SUM 10 : (Mul) F10dx from the MULTIPLICATION category. ### When can I use this method?

For multiplying any 2-digit number with another 2-digit number such that the sum of the first digits of the multiplier and multiplicand = 10 and the remaining digits of multiplier are same as that of the multiplicand.

For multiplying any 3-digit number with another 3-digit number such that the sum of the first digits of the multiplier and multiplicand = 10 and the remaining digits of multiplier are same as that of the multiplicand.

You cannot use this method to multiply numbers with unequal number of digits, i.e. multiplying a 2-digit number with a 3-digit number.

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[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQfCYQXmwzyaJTM6RbV85Jzw”] Download Practice sheet for MULTIPLYING NUMBERS WITH FIRST DIGITS SUM 10