After duplex numbers, let us learn multiplication by triplex numbers. As the name suggests, numbers like 111, 222, 333 are triplex numbers. The method is similar to that of multiplication by duplex ...

You probably haven’t had to do longhand math in years, but you do mental math every day. Or maybe you google math problems ten times a day, because you’ve forgotten how to do any math beyond your ...

In fourth grade, students focus most on using all four operations - addition, subtraction, multiplication, and division - to solve multi-step word problems involving multi-digit numbers. Fourth-grade ...

Now that we've learned the basics of lightning fast mental addition, mental subtraction, and mental multiplication, it's time to turn our attention to a few tips that will help you take your skills to ...