Multiplying By Specific Numbers
There
are certain ways to multiply specific numbers that are easier and faster than
using a more conventional way (i.e. using the FOIL
method).
By using these following methods you can save time and energy.
There are some circumstances in which several methods may be used.
In such cases, it is up to the individual to decide which is easiest and
fastest.
* = easy should be learned by Elementary level students
** = medium should be learned by Junior High level students
*** = difficult should be learned by High School level students
Note: Unless stated otherwise, all the steps will ask you to write the answer down reading from right to left. In other words, you will write down the one’s digit to the answer first, followed by the ten’s digit, followed by the hundred’s digit, and so on.
This section is to be used only if you are multiplying by a specific number. Sometimes it might be easier to use a different method from the Multiplying Strategies Section. The choice is purely yours as to which one is best!
(*) Multiplying by 5 (*PDF*) | |
(*) Multiplying by 11 (*PDF*) | |
(**) Multiplying by 12 - 19 (*PDF*) | |
(**) Multiplying by 15 (*PDF*) | |
(*) Multiplying by 25 (*PDF*) | |
(*) Multiplying by 50 (*PDF*) | |
(**) Multiplying by 75 (*PDF*) | |
(*) Multiplying by 101 (*PDF*) | |
(**) Multiplying by 111 (*PDF*) | |
(**) Multiplying by 125 (*PDF*) | |
(**) Multiplying by 143 (*PDF*) | |
(**) Multiplying by 167 (*PDF*) | |
(***) Multiplying by 286 (*PDF*) | |
(**) Multiplying by 375 (*PDF*) | |
(***) Multiplying by 429 (*PDF*) | |
(***) Multiplying by 572 (*PDF*) | |
(**) Multiplying by 625 (*PDF*) | |
(***) Multiplying by 715 (*PDF*) | |
(***) Multiplying by 858 (*PDF*) | |
(***) Multiplying by 875 (*PDF*) | |
(**) Multiplying by 1001 (*PDF*) | |
(**) Multiplying by 1111 (*PDF*) | |
(***) Multiplying by 3367 (*PDF*) | |
(***) Multiplying by 14443 (*PDF*) | |
(***) Multiplying by 101101 (*PDF*) | |
(***) Multiplying by 142857 (*PDF*) |