# How to make Mathematica less than 100 million not output by scientific counting

I want the result of 1200000000*0.001 to be 1200000. But Mathematica's output is in the form of scientific counting.

How can I make numbers larger than 1.*10^-8 and smaller than 1.* 10^9 output by scientific counting every time in Mathematica?

For example, for the number 1.231456785*10^6, I want the output to be 1231456.785 every time. It's better to save the settings to the configuration file.

## 1 Answer

Many ways to do this. You could always do

   $PrePrint = AccountingForm; 1200000000*0.001 Or, if you can change the number of digits $PrePrint = AccountingForm[#, 30] &;
1.231456785*10^6 Look up also number formating.

 1.*10^-8 1.*10^9 • For this number, the result of this code does not meet the requirements. Rationalize@1.231456785*10^6 – A little mouse on the pampas Apr 9 '20 at 5:42
• Check carefully the precedence of the operations Mathematica applies in evaluating Rationalize@1.231456785*10^6. It's not clear whether the failure to meet requirements you identify is genuine, or a misunderstanding. – High Performance Mark Apr 9 '20 at 11:43
• Thank you very much for your help. I can use the following settings to meet the needs, but after shutting down and restarting MMA, this setting will not work. How can I save it to the configuration file for permanent effect. \$PrePrint = ScientificForm[If[10^-5 < # < 10^6, #, N[#]], 15, ExponentFunction -> (If[-6 < # < 6, Null, #] &), DigitBlock -> 4, NumberSeparator -> " "] &; – A little mouse on the pampas Apr 10 '20 at 1:32