H.
Since you can't really know how much he's getting when breastfeeding, you can only really go back to the early days and watch what comes out....As long as he's wetting plenty of diapers and appears content about it, I'd say he's getting what he needs. If he's fussy and acting like he's not satisfied after a feed, then he's probably needing more. With the summer approaching and he's 10 months, it'd be a good time to also supplement with some water. Just put it in a sippy and let him have it at meals or even while he plays. He won't necessarily sit and take it like he does with a bottle of milk, but it's good for him to have access to it to just sip as he's interested/thirsty to keep hydrated. I started offering it to mine at 6 months when they started food. Even now at 3.5 and 2, they always like to have a cup of water someplace to just be able to grab and sip when they need it. You don't have to worry about it spilling, going bad, or rotting their teeth so it's fine for them to carry around and just sip off it throughout the day. Plus learning to drink fresh water is good for life.