Peter in the unlucky Brad picture book is Brad's classmate. In the chapter of grabbing gifts in the picture, Brad is curious about what gifts other students have prepared. Peter: "I brought Tyrannosaurus Rex," Zach: "My gift is Star Warrior. As we all know, Peter is Brad's classmate.

The picture book story "Bad Brad-Math Help" Xin Lei Publishing House tells a story that happened around a child, and naturally introduces a math knowledge from the problems in the story, and then uses it to solve the problems.