two heads are better than one

(proverb) it’s always better to have two people doing something

Example Sentences:

A: How are you doing with your presentation?
B: Not so good.
A: Do you want help?
B: Sure! Two heads are better than one.

The scientist asked his colleague to look at his work because two heads are better than one.

Similar idioms:

1. put our heads together
2. can’t make heads or tails of it