Party guests arriving, money in a wallet, distance walked in two trips, the
+ story is everywhere.
Mental math might use "make a ten" first:
9 + 6 = 9 + 1 + 5 = 10 + 5 = 15 because tens feel friendly. The next big operation is the
opposite move:
subtraction (Topic 8), "how much more?" or "what is left?", but it is still a cousin of the line:
count back or
compare the gap. For now, own the
sum: it is the honest count of a honest union.
🧁 TAKEAWAY
Add = join or hop right · + and = in sentences · Commutative & associative (school numbers) · Columns + carry = bundle tens · Check with estimate or second path.