Checkbox formula when two summary fields equal each other

Hi,

I am getting the operator '=' can't be applied on type bools with this formula:  

If(
[# of Medical Records]=[# of Medical records Received], true
)

I have a parent table and a child table. I want to have a checkbox that will be true when all records are received in the child's table.
I created two different summary reports. 
Can I get some help with this?
Thanks!

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Sandralee Oster
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