Mental Calculation, Mathematics, and Puzzles


Topic Replies Activity
About the Mental Calculation, Mathematics, and Puzzles category 1 October 27, 2018
Memoriad mental addition of ten 10-digit numbers 2 January 18, 2020
``Left to Right`` or ``Cross-Multiplication``. Which one is better? 11 January 18, 2020
Is Anyone Using Kaktovik Iñupiaq Numerals to Speed up Their Math? 28 January 18, 2020
Cross multiplication: How to multiply 3+ digit numbers? 17 January 17, 2020
9th Mental Calculation World Cup 2020 1 January 17, 2020
Help me to memorize (stock) numbers composed by more than 5 digits 9 January 8, 2020
9307 × 7992 by Soroban? 5 January 8, 2020
Alphabetical puzzle 4 December 30, 2019
A very easy mentally way to calculate logarithm 1 December 2, 2019
How to solve this Soroban addition? 7 December 17, 2019
What are your books about mental calculation? 3 December 14, 2019
Rinne Tsujikubo. 13 years old Japanese girl 9 December 14, 2019
De kunst van het hoofdrekenen (Art of Mental Calculation) 5 December 5, 2019
An alternative way to mentally calculate LOGARITHMS and ANTILOGARITHMS 1 December 3, 2019
Mentally calculating trigonometric values 1 December 2, 2019
Calculating squares and higher powers using division and addition 12 November 30, 2019
Visualizing a chess board 15 November 27, 2019
A completely different approach to calculating ln(2) 4 November 22, 2019
Calculating ln Natural Logarithms 3 November 16, 2019
Binary numbers techniques 18 November 15, 2019
Check out "Math - Quiz Game" 10 November 14, 2019
Multiply two squaring numbers 14 November 11, 2019
Squaring shortcut method 15 November 8, 2019
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