Common mistake
Working out doubling time as 100 divided by the rate
It sounds like this
“At 7% a year it'll take about 14 years to double — 100 divided by 7.”
Why it’s wrong
That is how long it takes if the growth is always taken on the first amount; growth on growth gets there sooner.
The lesson that fixes it
Cognosc spots mistakes like this.
When you explain something in your own words, Cognosc can tell exactly which mistake you’re making — not just that you’re wrong — and gives you a short lesson to fix that one thing.