How multiplications can be made easy with this genius maths hack using lines

mirror.co.uk:

What are you like at multiplications? Chances are if you're a mere mortal 2, 5s and 10s won't seem too taxing. But when it comes to figuring out what 42x21 is, you may wish somebody had shown you the Japanese multiplication method in school.

This genius Japanese multiplication method of drawing lines and dots is supposed to make doing multiplications so much easier, quicker and - wait for it - fun.

But does it work? Can you learn how to do it without any technical help or going back to the classroom (you know, when that's finally allowed!)?

Home-schooling mum Laura Davies got out her colouring pens to give it a go and this is how she got on. What is Japanese multiplication?