Question

Terry has $2.30 can she buy for pencils that cost $.49 each

Answer 1

If she has $2.30 yes she can buy pencils that cost $.49.

$.49 + $.49 = $.98 + $.49 = $1.47 + $.49 = $1.96.

She can only buy 4 pencils because if we added another $.49 that will equal $2.45 and she doesn't have enough money for that.

There is a shorter method which is:
$2.30 / $.49 = giving an answer of 4.69.
and although that would round up to 5. 
She doesn't have enough money so we round it down to 4.

Giving us an answer that she can only buy 4 pencils.

Answer 2

Well 2.3 divided by 0.49 equals
About 4.69, and you can't but part of a pencil so the answer is
She can buy 4 pencils.