Answer:
The techniques than can be used with an 87 year old man to be focus and to stay on task must be strengthen his focus and take short breaks.
Step-by-step explanation:
With elderly we have to be careful because at this age they do not concentrate for a long time on a thing or a topic so what you have to do is to strengthen his focus; for example, ask the patient only questions about one single topic (daily routines, family, economy, etc) and in this way the person will get interested and he/she will not lose the focus of the conversation and also, you can tell him/her about your own personal experiences related to the topic asked. In addition, you can also take short breaks while having the conversation if the person gets distracted very easily; for example, tell the person if he/she wants some coffee or water during the talk and stop fpr some seconds so the person feels more comfortable with you and in this way, you can notice if the person can come back to the topic asked easily and quicly.
I hope it works for you!