Here’s an example of a **SPEED MATH** shortcut for **MULTIPLYING NUMBERS WITH FIRST DIGITS SUM 100 : (Mul) F100dx **from the **MULTIPLICATION** category.

**When can I use this method?**

For multiplying any 3-digit number with another 3-digit number such that the sum of the initial digits of the multiplier and multiplicand = 100 and the remaining digits of multiplier are same as that of the multiplicand.

For multiplying any 4-digit number with another 4-digit number such that the sum of the initial 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.

[contentblock id=google-adsense-post]

[starrater tpl=10]

[tubepress mode=”playlist” playlistValue=”PLngU_U4dGjQcBKHCcZEPTSAtafu2cd3hV”]

** Download Practice sheet for MULTIPLYING NUMBERS WITH FIRST DIGITS SUM 100 **

[contentblock id=google-adsense-post]

**Notes –**

- Notice the way the common digits are added.
- When multiplying 3-digit numbers with common last digit, remember to write the RHS of the answer in 2-digit form by prefixing a zero, if the value is single digit, e.g. write ‘9’ as ‘09’.
- When multiplying 4-digit numbers with last 2 digits common, remember to write the RHS of the answer 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 first digits sum 10: (Mul) F10dx

Multiplying Numbers with first digits sum 1000: (Mul) F1000dx

[contentblock id=speedmath-blockquote]