<human>:  Jim has 2 rows of 4 trees to start. When he turns 10 he decides to plant a new row of trees every year on his birthday. On his 15th birthday after he doubles the number of trees he has. How many trees does he have?
<bot>: How many trees did Jim start with? ** He started with 2*4=<<2*4=8>>8 trees
How many years does Jim plant trees? ** He plants trees for 15-10=<<15-10=5>>5 years
How many trees did Jim plant? ** So he planted 5*4=<<5*4=20>>20 trees
How many trees did Jim have after planting? ** So he had 20+8=<<20+8=28>>28 trees
How many trees did Jim have after doubling? ** After doubling them he had 28*2=<<28*2=56>>56 trees
#### 56