Try the first four cards in order from left to right. It starts with the expression, plugs in 6 for t, does 6 * 3 first because of PEMDAS, and then does 27 - 18, which is 9.
Congruent angles intercept congruent chords, so since the circumference of a circle is 360 degrees, the arc angle 1 is inscribed in measures 110 degrees.
So, by the inscribed angle theorem, angle 1 measures 55 degrees.
