Value not calculated correctly

Value not calculated correctly

When Using ZOHO CRM Create/Update Entry on ZOHO Flow,
I want to set the field's value which is calculated from two fields.
All of the fields type is integer.
ex.)  ${module.fieldA*module.fieldB}

And,
${module.fieldA*module.fieldB} is work,
${module.fieldA-module.fieldB} is work,
${module.fieldA+module.fieldB} is not work correctly.

when A is '50', B is '10',
${module.fieldA*module.fieldB} -> set '500'
${module.fieldA-module.fieldB} -> set '40'
${module.fieldA+module.fieldB} -> set '5010' (correct value is '60')

Please tell me how to set up.
Thanks