[HELP] Pension Accting - Calculating Actual Plan Asset Return

Hi, As a lot of you Schweser users already know, the Pension section is presented very differently in the CFAI books that it is in Schweser. In CFAI actual return on assets in plan assets is presented differently, My specific question is in regards to EOC question #11 (p135 in CFAI), which asks about the actual return on Passaic’s plan assets. The answer in the back says that the actual return is the expected return + the actuarial gain. However, on pg 118 in the example, the actual returns on plan assets is calculated as either 1) the sum of each item that increases or decreases the fair value of the plan assets (other than benefits paid and contributions) OR 2) the change in fair value of the plan assets adjusted for contributions and benefits paid. Fundamentally, these seem like very different and conflicting ways of getting at actual return on assets. Does anyone know why??