Edit 
				
					"when" : [
    {
        "blockType":"when",
        "blockOptions":{
            "method":{
                "name":"compareNumbers",
                "args":{
                    "item":"item",
                    "comparator":"comparator",
                    "value":"value"
                }
            }
        },
        "fields":[
            {
                "name":"item",
                "type":"item",
                "value":"5de64f6a70c7be0541cc0853"
            },
            {
                "name":"comparator",
                "type":"string",
                "value": ">"
            },
            {
                "name":"value",
                "type":"int",
                "value": 51
            }
        ]
    },
    {
        "blockType":"when",
        "blockOptions":{
            "method":{
                "name":"compareNumbers",
                "args":{
                    "item":"item",
                    "comparator":"comparator",
                    "value":"value"
                }
            }
        },
        "fields":[
            {
                "name":"item",
                "type":"item",
                "value":"5de64f6a70c7be0541cc0854"
            },
            {
                "name":"comparator",
                "type":"string",
                "value": "<="
            },
            {
                "name":"value",
                "type":"float",
                "value": 51.55
            }
        ]
    }
]
Edit
Use an expression value to compare with an item updated value. The event will raise in a situation when an item value meet the expression value: – the item value is changed; – the expression value is changed. 
				
					"when" : [
    {
        "blockType": "when",
        "blockOptions":{
            "method": {
                "name": "compareNumbers",
                "args": {
                    "item": "item",
                    "comparator": "comparator",
                    "value": "value"
                }
            }
        },
        "fields": [
            {
                "name": "item",
                "type": "item",
                "value": "5de64f6a70c7be0541cc0853"
            },
            {
                "name": "comparator",
                "type": "string",
                "value": ">"
            },
            {
                "name": "value",
                "type": "expression",
                "value": "expressionName"
            }
        ]
    }
]
See Scenes expression related commands for detail on creating expressions.
Edit
Compare value of an expression with name “expressionLeft” with a value of an expression with name “expressionRight”. The event will raise when value of “expressionLeft” becomming greater than value of “expressionRight”. Event checked whenever values of “expressionLeft” or “expressionRight” are changed. 
				
					"when" : [
    {
        "blockType": "when",
        "blockOptions":{
            "method": {
                "name": "compareNumbers",
                "args": {
                    "expression": "expression",
                    "comparator": "comparator",
                    "value": "value"
                }
            }
        },
        "fields": [
            {
                "name": "expression",
                "type": "expression",
                "value": "expressionLeft"
            },
            {
                "name": "comparator",
                "type": "string",
                "value": ">"
            },
            {
                "name": "value",
                "type": "expression",
                "value": "expressionRight"
            }
        ]
    }
]