There are 9-4 = <<9-4=5>>5 blue pens left in the jar.

There are 21-7 = <<21-7=14>>14 black pens left in the jar.

There are 5+14+6 = <<5+14+6=25>>25 pens left in the jar.

# Answer

25
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
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?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
25
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?
train