Knowing your multiplication facts is very useful, but what happens when the numbers you are multiplying are greater than those in your multiplication tables? You will need to calculate using a column ...

Some seemingly simple sequences of multiplication and addition grow so quickly that they question the very foundations of ...

Four-digit numbers can be partitioned into ones, tens, hundreds and thousands. Understanding the value of each digit makes it easier to compare numbers using the less than (<), greater than (>) and ...