Being Prepared for Division

For many, long division is a topic that is somewhat understood, but not fully mastered.  Mastering long division typically involves a lot of trial-and-error. That is the way most people learn it, which can be time consuming and frustrating. The great news is that it doesn’t need to be that way!  The first step to mastering long division is making sure your multiplication tables are solid. These two operations are closely related.  There are many online resources and games to help with brushing up on multiplication facts. Mastery of multiplication facts gives students a head start in tackling any division problem. If your child or student is putting in extra math practice time, check out a post I recently wrote on making math fun. CLICK HERE to read the article!

Estimation Method

Dividing by one number is usually well-understood by students with a little practice; however, many would benefit with more help in the area of dividing by a 2-digit number.  There’s a great “trick” that involves estimation that’s worth sharing for those struggling with dividing by a 2-digit number.  I’ll demonstrate with an example below:

2950 ÷ 38

Step #1:  Round the divisor to the near tens place (so, this makes 38 become 40)

Step #2:  Ask yourself:  how many times does the first digit of the rounded divisor (40) go into the first two digits of the dividend (2950) without going over?  So in this case, 4 goes into 29 seven times (4×7=28)

Step #3:  Multiply the original divisor by that number (7):  38×7 = 266.  We see that 7 is the correct number to use in our quotient because 266 goes into 295 without going over.

Step #4:  Subtract and bring down just like you’ve been taught for all division problems

Step #5:  Repeat steps #1-4 until the division problem is completed

Give it a try!  Most students love this method once they get the hang of it (which is typically very quickly) because the amount of guessing has been greatly reduced from the process.  Using this method, you will never be further away than one iteration from the correct answer, and usually you’ll be correct on the first try.  This is a big improvement from the old, classic method of guessing numbers and multiplying until you find what works best.  Now you can have fun with mastering long division!