I bought a Mastercraft Digital Multimeter at Canadain Tire. Igor, my assistant, suggested I buy one. We have some spare body parts that we want to put together. He said that we would need to test for high voltage during the process.
I could not figure out how to install the nine-volt battery that was included. I spent an eternity looking at the back and front of the multitester. Finally, I gave up.
Gadget Rule Number 1:
When all else fails, read the instructions.
I read through the instruction manual. Nowhere— NOWHERE!—does it tell you how to install the battery. I read through the instruction manual a second time and a third time, and a forty-seventh time. Nowhere does it tell you how to install the battery.
It was back to Canadian Tire to solve the greatest mystery of all time: How to install a battery in a Mastercraft Digital Multitester.
The woman at the Service Desk examined the back and front of the Multitester. After a pause, she asked, “Did you check the instructions?”
“Yes,” I said.
And then she checked the instructions twice.
“Well,” she said, “take it down to the hardware desk. I’ll call someone to help you.”

The rectangular shape is not a battery compartment. It folds out to make a stand.