human
Calculate percentage of an amount mentally where the percent is a multiple of 10 Tom and Katie are arguing about working out percentages of amounts.

Tom says to find \( 40 \% \) you divide by \( 100 \) and multiply by \( 4 \). 
Katie says to find \( 40 \% \) you divide by \( 5 \) and multiply by \( 2 \).
Who is correct? Only Tom
gpt
Believes that dividing by 100 gives 10%