In order to empower women in business and tech, we need groups of women and men supporting them, Gates and Sandberg said.
Sandberg discussed the power of peer mentorship, citing how her Lean In networking and support circles in computer science and engineering has grown to more than 7,400 members.
"We found that peer support can be so important," Sandberg said.
Furthermore, companies need to increase the number of women on their boards and in their C-suites, Gates added.
If "you have one woman on a board, she's not going to be able to make the change," she said. "You need several women on the board to make the change."
"Pull other women up with you," Gates said. "Bring them along."