Keyboard shortcut (Cntrl 1-7) not working on my Macbook Air (2015), how do I fix this?

I used this shortcut (Cntrl 1-7) on another Mac laptop once, but for some reason, it doesn't work on mine (2015 Macbook Air), and I can't figure out how to fix it. I am a photographer and want to use it to put the color tags on pictures while I'm viewing a lot at a time.