In sum
Definition 1 of 1
Pro Tip 1/3Wrap-up Signal
Use 'in sum' to indicate you're summarizing or concluding your thoughts. 
In sum, our team's effort led to our success.
Pro Tip 2/3Academic Context
'In sum' is often used in essays or formal writing to introduce a conclusion. 
In sum, the data supports our hypothesis.
Pro Tip 3/3Not for Calculations
Don't confuse 'in sum' with mathematical summing; it's not about adding numbers. 
In sum, the story's themes are complex and multifaceted.