# Using Multiple Operators in an Assignment Rule
Sometimes you may need to perform operations in assignment rules that use operators such as ‘Add’, ‘Subtract’, etc. (Note that ‘Add’ is both a mathematical operator – add the values of two fields together – and also a text concatenation operator – add one string to the end of another string.)
To perform these operations, you send the multiple operators in a single ‘operands’ array, as shown below where we are assigning the value from the ‘balance’ field in the acts\_view to ‘test\_number’, and then subtracting 525 from that value.
```
{
"context": {
"user": "user_ID",
"password": "XXXX",
"project": {
"name": "imp_payments_demo",
"version": "1.0"
},
"workSet": {
"name": "api_2_workset",
"version": "1.1"
}
},
"entity": {
"step": {
"name": "imp_enter_details",
"version": "1.0"
},
"attribute": "test_number",
"operands": [
{
"operator": "ASSIGN",
"value": {
"name": "acts_view",
"version": "1.0",
"attribute": "balance"
}
},
{
"operator": "SUBTRACT",
"value": "525"
}
]
}
}
```
When run in TDO, the response message for a successful call will look very similar to other rules assignment messages. Both of the operators and their values will be reflected in the return message.
Return Message using multiple operators
In TDO, after this call runs, you will see the rule assigned to the field.
