The Number Field stores a simple number in the value
property.
{
"PO #": {
"value": "2345",
"id": "de084048-ba11-45a2-bf29-a46c0108d3c5",
"name": "PO #",
"type": "Number"
}
}
NOTE
The id, name, and type are not necessary when creating or updating a form, they are returned in the JSON of a request for readability.