(−11) + (−2) + (−1) = ______.
−14
Idea: When we add negative numbers, we add their sizes and keep the minus sign.
Step 1: Add the sizes (ignore the signs for now).
\(11 + 2 = 13\)
\(13 + 1 = 14\)
Step 2: All numbers were negative, so the sum is also negative.
\(-14\)
Check by grouping:
\((-11) + (-2) = -(11+2) = -13\)
\(-13) + (-1) = -(13+1) = -14\)