When you are solving an addition calculation with a two-digit number, you need to think about tens and ones. A place value chart can help you to see the value of each digit in a number. For example, ...

When you are adding larger numbers, it’s often better to use a written method. Column addition is a good written method to add one number to another. It involves putting the digits of each number into ...

Practice time! Build, read, & write three-digit numbers using base-10 blocks and symbols. Practice time! Build, read, write (in standard and expanded form), and represent three-digit numbers using ...