The Hardest Addition and Subtraction Questions in the World!

 $6+9$  

 $19-4$  

 $48+56$  

 $153-84$  

 $5413+2064$  

 $9713-4284$  

 $15615+84151$  

 $94615-51515$  

 $881551+515547$  

 $941545-154815$