Multiply any large number by 12 mentally in seconds
To multiply any number by 12 just double last digit and thereafter double each digit and add it to its neighbor
For example 21314 * 12 = 255768
Lets break it into simple steps:
Step 1: 021314 * 12 = _____8 (Double of Last Digit 4= 8 )
Step 2: 021314 * 12 = ____68 (Now Double 1= 2, and add it to 4, 2+4=6)
Step 3: 021314 * 12= ___768 (Now Double 3=6, and add it to 1, 6+1=7)
Step 4: 021314 * 12= __5768 (Now Double 1=2, and add it to 3, 2+3=5)
Step 5: 021314 * 12= _55768 (Now Double 2=4, and add it to 1, 4+1=5)
Step 6: 021314 * 12= 255768 (Now Double 0=0, and add it to 2, 0+2=2)
So your final answer of 21314 * 12 = 255768
