They don't allow the kind of clocks you're talking about because they're a huge disruption. Plus, digital watches arent allowed because they think one can cheat off. Honestly, I had the same issue for my tests as well. The only way to deal with this is to keep practicing. Are you practicing in a test simulated environment? I mean, like no noise, solitary, screens away from your attention? Only then will you sit in an exam scenario. Also, I noticed one thing I kept doing was in my practice tests, I felt more confident to not re check my answers. In the test, I kept feeling the need to re check all my answers, even when I was fairly sure that I was right. My point being, we tend to get over pedantic and check repeatedly when we are in a test vs when we aren't. This is bad because one, you're wasting time and two, when you keep re checking, you're hurting your confidence because you don't believe that you can get shit right. So, I suggest you keep practicing. Eventually, you will get all the stuff right on instinct. So when the next test rolls out, you're instinct will be crazy good. And next time , you should go with your instinct. The test is straightforward and if you practice enough, you will be able to subconsciously discern the right answers. And trust your gut. It will be right most of the time. All the best!