Joe’s dad roasts 21/3 = <<21/3=7>>7 of his marshmallows.

Joe has 21*4 = <<21*4=84>>84 marshmallows.

Joe roasts 84/2 = <<84/2=42>>42 of his marshmallows.

Joe and his dad roasted 7+42 = <<7+42=49>>49 marshmallows in total.

# Answer

49
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Joe goes camping with his dad on a Friday. Joe's dad has 21 marshmallows, and Joe has four times as much marshmallows as his dad. If Joe’s dad roasts a third of his marshmallows, and Joe roasts half of his marshmallows, how many marshmallows did they roast in total?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
49
Joe goes camping with his dad on a Friday. Joe's dad has 21 marshmallows, and Joe has four times as much marshmallows as his dad. If Joe’s dad roasts a third of his marshmallows, and Joe roasts half of his marshmallows, how many marshmallows did they roast in total?
train