## Algebra 1

To find the final reading on the barometer, add each amount by which the mercury rises and subtract the amount by which the mercury falls. $29.8+0.02-0.09-0.18+0.07\longrightarrow$ use commutative property to group positive and negative numbers together $=29.8+0.02+0.07+-0.09+-0.18\longrightarrow$ add the positive and the negative addends $=29.89+(-0.27)$ add $=29.62$