Final answer:
To calculate the amount of money your class collects for selling 6 calendars, you can use mental math and the distributive property. The expression $2.90 x 6 = $17.40 can be used to easily do the calculation mentally.
Step-by-step explanation:
To calculate the amount of money your class collects for selling 6 calendars, you can use the distributive property. First, calculate the cost of one calendar by multiplying $2.90 by 6:
$2.90 x 6 = $17.40
So, your class collects $17.40 for selling 6 calendars.