Question

What is 334.54 + 198 grams

Answer 1

ANSWER without rounding: 532.54 grams 

Question: Is this a significant figures question?

ANSWER round to the significant figures: 533 grams

When you do addition you use the number with the least number of decimals places to determine how many decimal places will be in your answer. There are no decimal places in 198 so you would round before the decimal place in the answer (ones place).

Answer 2

334.54 + 198 = 532.54 grams total

hope this helps