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Multiplication Multiplying Numbers with last digit sum 100 Speed Math

[Speed Math] MULTIPLYING NUMBERS WITH LAST DIGIT SUM 100

Here’s an example of a SPEED MATH shortcut for MULTIPLYING NUMBERS WITH LAST DIGIT SUM 100: (Mul) S100dx from the MULTIPLICATION category.

Multiplying Numbers with last digit sum 100

When can I use this method?

For multiplying any 3-digit number with another 3-digit number such that the sum of the last 2 digits of the multiplier and multiplicand = 100 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 2 digits of the multiplier and multiplicand = 100 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 3-digit number with a 4-digit number.

 

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pdf Download Practice sheet for MULTIPLYING NUMBERS WITH LAST DIGIT SUM 100

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Notes –

  1. The RHS of the answer should always be written in 4-digit form by prefixing zero(s), if the value is less than 4-digit, e.g. write ‘9’ as ‘0009’ or ’21 as ‘0021’ or ‘121’ as ‘0121’.

Related Shortcuts –

Multiplying Numbers with last digit sum 10: (Mul) S10dx
Multiplying Numbers with last digit sum 1000: (Mul) S1000dx

 

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