NumberNut
Number Nut: Subtraction: 3 Digit Numbers
A brief lesson on subtracting from three-digit numbers that includes detailed examples, rules, and further explanation of borrowing.
Math Is Fun
Math Is Fun: Place Value
Find out what the "tens" and "hundreds" columns are and how they can help you understand a numbers place value. Learn what each digit of a number stands for with the help of charts used at this MathsIsFun resource.