Fermat's Library on Twitter: "Any number dialed in a rectangular shape on a calculator numpad is a multiple of 11 https://t.co/RChNIjb8Mu" / Twitter
Fermat's Library on Twitter: "Here's a quick method to calculate the square root of a number (√y) by hand https://t.co/vqVqXnt3mV" / Twitter
![NEW LOOK & MODEL. Casio scientific calculator fx-991ZA PLUS II (Replacing fx-991ZA ) - AdMaths Retail NEW LOOK & MODEL. Casio scientific calculator fx-991ZA PLUS II (Replacing fx-991ZA ) - AdMaths Retail](https://www.admathsretail.co.za/wp-content/uploads/2021/02/calc.jpg)