If you go to a pizza restaurant and ask them to "Divide two (large pizzas) into four (portions)" they would indeed give each person 1/2 pizza. So for colloquial

If you go to a pizza restaurant and ask them to "Divide two (large pizzas) into four (portions)" they would indeed give each person 1/2 pizza. So for colloquial use you are correct. Which makes the math definition confusing.