You got your result: 27x34=918 Method 3: Rounding and Adjusting This method is fantastic when one or both numbers are close to a multiple of 10 (e.g., 19,21,48,52). You round, multiply, and then ...

In this KS2 Maths article you’ll learn how to use short multiplication to multiply a 3-digit number by a 1-digit number. We also have a KS2 Maths quiz and lots of examples.

This Maths article explains both the mental method and written method for multiplying a 2-digit number by a 1-digit number.

Schönhage and Strassen predicted that an algorithm multiplying n -digit numbers using n * log (n) basic operations should exist, Harvey says. His paper is the first known proof that it does.