Juan ran the lemonade stand for 3 more days. Each day, he used the money from sales to purchase more lemons, cups, and sugar to make more lemonade. On day 2, he earned $16 and spent $7 on supplies. On day 3, he earned $22 and spent $12. The expression 16 – 7 + 22 – 12 can be used to model the situation for these 2 days.
The associative and commutative properties can be applied only to problems with addition. Juan had to change the subtraction to addition by adding the additive inverse.
