Meet Engineer Ninja! A growth mindset is all you need when you create and build something from scratch. Find out what happens when perfectionism stands in the way of building the most perfect flying machine! Today, I designed a machine Built to fly, With bolts and gears To reach the sky. Life is hard! It's even harder for children who are just trying to figure things out. The Ninja Life Hacks book series is: Geared to kids 4-10+ Perfect for boys & girls Early readers Grades K - 6th grade and up Excellent resource for counselors, parents, and teachers alike Collect the entire Ninja Life Hacks book collection and box sets!.