In what situations would it be necessary to manually adjust calculations in PHP to ensure accurate results when dealing with numbers and pagination?

When dealing with numbers and pagination in PHP, it may be necessary to manually adjust calculations to ensure accurate results when the number of items per page does not evenly divide the total number of items. This is especially important when calculating the total number of pages or the offset for fetching items from a database. To solve this issue, you can use functions like ceil() or floor() to round up or down the result of division to the nearest integer.

$totalItems = 105; // Total number of items
$itemsPerPage = 10; // Number of items per page

$totalPages = ceil($totalItems / $itemsPerPage); // Calculate total number of pages
echo "Total Pages: " . $totalPages;

$pageNumber = 6; // Current page number
$offset = ($pageNumber - 1) * $itemsPerPage; // Calculate offset for fetching items
echo "Offset: " . $offset;