Yes, multiple posit additions can be done in the quire, a wide fixed-point register, with no rounding error until you convert the quire value back into posit form. This restores the associative property of addition, for situations where that is desirable. For 8-bit (standard) posits, the quire is 128 bits long so you can sum up to about 3.6e16 numbers with no possibility of overflow. (and they would all have to to be the maximum posit value, 2^24, to overflow). For 16-bit posits, you can sum up to about 1.5e26 numbers with no possibility of overflow. You might be able to hit that maximum with the fastest existing supercomputers and a lot of patience, but otherwise you're safe to consider it impossible to overflow. The quire is 256 bits long for 16-bit posits. For 32-bit posits, you'd have to add the largest posit to a sum over 2.9e45 times before there is any way to overflow. Now we're talking about numbers you can't reach even if every atom on Earth is also a computer. The quire is 512 bits long, the same sie as a cache line on many microprocessors.