Adding and subtracting fractions. HASSAN:I bet this was a temple. OLIVIA:And this was a massive pillar. HASSAN:Does this go together with this? OLIVIA:Hmm, not sure. HYPATIA:Sorry it's a bit of a ...

Adding and subtracting using mental methods. OLIVIA:What are we dealing with Hassan? HASSAN:Eight trip wires, three spike traps, five swinging blades, six crocodiles, four lurking crocodiles and ...