Good example. Perhaps they're trying to encourage you to tip in whole numbers, further away from your "mental anchor" than you would with a number like $8.99.

Good example. Perhaps they're trying to encourage you to tip in whole numbers, further away from your "mental anchor" than you would with a number like $8.99. Maybe a $10 meal nets a carefree $2 tip whereas a $9.99 meal merits a meticulous $11.49 total in the customer's head.