From tecmath: Percentages can be done mentally as quickly as you can work out basic multiplication. Use this trick to work out percentages instantly. Credit: https://www.youtube.com/watch?v=_BPY1lMO5r0
From tecmath: Percentages can be done mentally as quickly as you can work out basic multiplication. Use this trick to work out percentages instantly. Credit: https://www.youtube.com/watch?v=_BPY1lMO5r0