Before the purchase, Bert had 300 * 1/2 = <<300*1/2=150>>150 stamps.

So after the purchase he has 300 + 150 = <<300+150=450>>450 stamps.

# Answer

450
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Bert bought some unique stamps for his collection. Before the purchase, he had only half the stamps he bought. If he bought 300 stamps, how many stamps does Bert have in total after the purchase?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
450
Bert bought some unique stamps for his collection. Before the purchase, he had only half the stamps he bought. If he bought 300 stamps, how many stamps does Bert have in total after the purchase?
train