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? Neither is correct
gpt
Unable to equate a division and multiplication to a single division