Laravel update multiple rows using checkboxes

I need to understand how to use the laravel eloquent way to update multiple rows in a database, based on which checkboxes have been checked. I am using the following code right now, which is working to a certain extent:

public function save()
{
    $post_data = Input::get('checkbox');

        if(is_array($post_data))
        {
            foreach ($post_data as $checkbox)
            {
                    $product        = Products::find($is_checked);

                if(!empty($checkbox))
                {
                    $product->is_checked    = '1';
                }
                else {
                    $product->is_checked    = '0';
                }
                    $product->save();
            }
        }

    Session::flash('success', 'Success message here');
    return Redirect::to('overview');
}

It does save the "is_checked" values, when a checkbox is selected. In the database it sets the value to "1". But if I uncheck a checkbox, it does not update the row and the "is_checked" stays at "1".

But that is not my main concern. What I wish to do, is not to use a foreach for this, because I need to update multiple rows each time, usually I need to update 100+ rows, so running 100 seperate queries is not the way to go.

First question: How do I update multiple rows in my mysql table by checking or unchecking checkboxes using the laravel eloquent model?

Second question How do I update other fields with different values based on which checkbox has been selected and based on the dropdown that comes with it? Example below:

<form name="bla">

<input type="checkbox" name="checkbox[]" value="{{ $id from database }}>
<select name="number">
<option value="1">1</option>
<option value="2">2</option>
And so on..
</select>

</form>

I have multiple checkboxes with a select menu behind it. What I wish to accomplish is the following:

[x] Checkbox with ID 1 - Select menu option selected = 1

[x] Checkbox with ID 2 - Select menu option selected = 5

[x] Checkbox with ID 3 - Select menu option selected = 10

When I select three checkboxes, all 3 corresponding rows should be updated in the database. So in the above example, the following should happen:

Database row with id 1 should get a "1" value for "is_checked" and the "number" field should be "1" Database row with id 2 should get a "1" value for "is_checked" and the "number" field should be "5" Database row with id 3 should get a "1" value for "is_checked" and the "number" field should be "10"

I hope this explanation makes it clear as to what I want to accomplish and I hope it is not confusing in any sort of way.