Assistance Multiplying 2 SQL Variables in Canvas

Elastic Stack Kibana
5

The number is stored in the cell but debug shows the number in a text field. Could that be my problem? Do I need to somehow change the field to a numeric?

filters
| essql query="SELECT 1+3 AS foo"
| math "foo"
| render as="debug"

This gives:

{
   "text": "4"
}