Answer:
aprox 280
Step-by-step explanation:
if you need to add these numbers quickly you can estimate either with an overestimation or under estimation:
for an over estimation, you can find the nearest 10 or 100 that each value is so for this you have 92 + 91 +92 +9 which is close to 100 +100+100+10
so using this you can quickly guess that it would be somewhere around 310
for an under estimation you can do the same thing but rounding down so we instead would add 90 + 90 + 90 + 10 which gives 280
now using both we know the answer would be somewhere between 280 and 310