Mental Calculation, Mathematics, and Puzzles


Topic Replies Activity
More repetition fun in division 6 November 8, 2019
Multiply into double no 4 November 8, 2019
Some special case in multiplication 6 November 6, 2019
How to calculate square root of complex no in mind 5 November 6, 2019
Fast division by 23 9 November 6, 2019
**Conjugate of complex no** 1 November 6, 2019
Think! There is always an easier way 29 November 6, 2019
Special number 1001 9 November 5, 2019
How to learn tables of maths 1 November 5, 2019
Best way to calculate + commit to memory a table with odds/ratios/%? 12 October 31, 2019
How to calculate factorial number 4 October 31, 2019
How to do calendar calculations 5 October 23, 2019
Duplex method for square roots 4 October 20, 2019
How to calculate day from date of birth 8 October 20, 2019
Multiplication table (99x99) 6 October 18, 2019
Multiplication a more efficient algorithm 1 October 17, 2019
Three digit division 4 October 17, 2019
How to calculate squares quickly 8 October 17, 2019
Divisibility and simple osculators 4 October 16, 2019
Division Mentally 6 October 15, 2019
Mental Multiplication: Useful Facts and Exercises 5 October 12, 2019
Expert mathematicians stumped by simple subtractions 6 October 11, 2019
Is abacus speed calculation really useful or just a gimmick? 10 October 7, 2019
Mental Calculation - Basics ( Complements ) 8 October 7, 2019
Prime numbers... useful applications? 8 October 6, 2019
Left to Right method for large numbers | Carrying problem 9 October 5, 2019
Avoiding the carry 8 October 2, 2019
Calculating Logarithms on a Soroban 2 October 2, 2019
Soroban Finger Exercises 4 October 1, 2019
Mental Abacus 10 September 30, 2019