Strength in Numbers centers around the lives of three women as they overcome professional and personal challenges. While there is financial literacy sprinkled throughout the book, the story mainly addresses the emotional impact money has on a family and how to overcome fear and self-doubt.

The story begins with Tony Positano, a financial planner, addressing the call of a concerned lottery winner. She has just three weeks to claim over three hundred million dollars and doesn't want her husband involved. A year earlier, Kate Becker is struggling to accept that her twenty-seven-year marriage is most likely over. Determined to rebuild her life one piece at a time, Kate begins to take small steps forward on her own. Meanwhile, Rachel Becker has been on maternity leave for the past four weeks. When her husband agrees to stay home with the baby, she returns to her job as an actuary where new challenges await. But as she, Kate, and other women learn to manage their money and relationships through inevitable obstacles, none realize that life will eventually reward them in ways never imagined.