JMeter , Execution order is not correct

I have 4 transaction controllers named

Trans_api1
__Http Request
Trans_api2
__Http Request
Trans_api3
__Http Request
Trans_api4
__Http Request

that contain Http Requests, However when I run my test plan, I want them to run in numerical order but then they run randomly. How do I fix the order to it runs from 1-4?