Cara was using her calculator to solve a problem. the answer that displayed was 1.6e+12. she knows that she entered all of the numbers correctly. why did the calculator give the answer it did? what is the answer to cara's problem?

1- Because the display Cara´s calculator does not support all the numbers. Then her calculator displays the number in scientific format.

2- The answer to Cara´s problem is: 

1.6E+12 = 1.6 x 10¹²  = 1,600,000,000,000 

One trillion 600 billion

Bons Estudos!

The answer to the problem she entered was 1,600,000,000,000.

But most calculator displays show 10 digits, so anything larger
than 999,999,999 could not display.

Instead, the calculator is designed to show very large (or very small) numbers
using scientific notation.  In that format, her answer is displayed as

1.6 x 10¹² , or, on the calculator,  1.6 E+12.  The 'E' means 'exponent of 10".

What is the question that you needed answered?