Since there's a pandemic and it's quite hard to understand those words in the book, I downloaded this and it helped me a lot! Thanks for making this app helpful for us students :). Really helpful,even the free version.
Place Value Disks
This webpage is all about disks math. You'll learn how to calculate the area and circumference of a disk, as well as how to find the volume of a cone.
Disk -- from Wolfram MathWorld
Solve math equations
Figure out mathematic question
Clarify mathematic equation
Expert instructors will give you an answer in real-time