Shortcodes not being in a specified position

I have this function that i placed using a shortcode but no matter where i place the shortcode it will stay at the top of the page instead of the staying inside the div or table i placed the shortcode in and thereby pushing every other div or text downwards.

Here is the example:

function show_age() {
echo ‘age is 29’;
}
add_shortcode(‘showcode’ ‘show_age’)