Dora made 8 cupcakes per hour for 5 hours for a total of 8*5 = <<8*5=40>>40 cupcakes
Betty took a 2-hour break so she spent 5-2 = <<5-2=3>>3 hours making cupcakes
Betty made 10 cupcakes per hour for 3 hours for a total of 10*3 = <<10*3=30>>30 cupcakes
The difference between the number of cupcakes they made is 40-30 = <<40-30=10>>10 cupcakes
#### 10