In the age of smartphone calculators and voice assistants, multiplying large numbers by hand may seem like a quaint and entirely unnecessary skill. However, you never know when you’ll need to do quick maths, and the Japanese multiplication method (also called multiply-by-lines) can help you figure out the answer simply…
Now you can get the top stories from Lifehacker delivered to your inbox. Enter your email below.
By subscribing you agree to our Terms of Use and Privacy Policy.