My question is: A jar contains 9 blue pens, 21 black pens, and 6 red pens. Four blue pens are removed and then seven black pens are removed. How many pens are left in the jar? Your thoughts:
There are 9 - 4 = 5 blue pens left in the jar. There are 21 - 7 = 14 black pens left in the jar. There are 5 + 14 + 6 = 25 pens left in the jar. The final answer: 25.