round to the highest place value then divide: 383/124 show your work

Question

Estimating quotients.

 

Example 41297/5

 

Look at the two highest digits in the dividend, 41. this cannot be evenly divided by 5 so round to the closest compatible number, 40

 

40 / 5 = 8

 

Add placeholder zeros to the estimated quotient for the place values you ignored in the original dividend.

 

41297 / 5  is about 8,000

 

 

How would I figure out 383/124 using the method shown above, show your work.

Answer 1

Estimating is intended to be so easy that you can do it "in your head."  That means "without a calculator, a computer, ..., or even paper."

 

There are different levels of estimating depending on how good you get with doing math "in your head," so at least a little paper is usually allowed.

 

In this problem 383 is close to both 400 and 375.  The problem and your ability determines which you choose.  Then, there is 124, which is very close to 125, and close to 100 for those less skilled.

 

Let's be less skilled --  400 / 100  is roughly 4.    (Dah !)

 

Let's be more skilled --  375 / 125 is roughly 3     (not bad for a beginner!)

 

Well, what's the exact value?  3.08871 (per Excel)  I'd say that the beginner's estimate was pretty close.  Take it!