Automatically updating post titles when a number in the content changes can be approached programmatically depending on the platform you’re using. The general approach is:

1. Detect changes in the content: Implement a listener or hook that triggers whenever the content of a post is updated.
2. Parse numeric values: Use a regular expression or structured data parsing to identify the number(s) in the content that should influence the title.
3. Update the title dynamically: Once a change is detected, programmatically update the post title using the platform’s API. For example, in WordPress, you could use hooks like save_post and functions like wp_update_post() to modify the title.
4. Validation and formatting: Ensure that the new title maintains readability and conforms to any SEO or platform constraints. For example, you might format the number consistently (e.g., 1,000 instead of 1000) and preserve any prefix/suffix text.

Example (pseudo-PHP for WordPress):

add_action('save_post', 'update_title_with_number');
function update_title_with_number($post_id) {
    $post_content = get_post_field('post_content', $post_id);
    preg_match('/\d+/', $post_content, $matches);
    if(!empty($matches)) {
        $number = $matches[0];
        $new_title = "Updated Post: $number units";
        wp_update_post(array(
            'ID' => $post_id,
            'post_title' => $new_title
        ));
    }
}

This ensures that the title reflects the current numeric content automatically without manual intervention.