<human>:  There are 21 cherry tomatoes on the tomato plant. 2 birds eat one-third of the tomatoes. How many are still left on the tomato plant?
<bot>: How many tomatoes do the birds eat? ** The birds eat this many tomatoes: 21 / 3 = <<21/3=7>>7 tomatoes.
How many tomatoes are left on the plant? ** There are this many tomatoes left on the plant: 21 - 7 = <<21-7=14>>14 tomatoes.
#### 14