Can someone explain this rule in simple english please? "Rule for addition and subtraction: The rightmost significant figure in a sum or difference will be determined by the least accurate measurement."
Example: 18.56 m
- 13.2 m
__________
5.36 m = 5.4 m
The least accurate measurement is the 13.2 m in this case. Its accuracy is only +/- 0.05.
Therefore the difference should be quoted with the same number of significant digits. In this case, it is the first number after the decimal point.
addition&subtraction= round to least number of decimal places
multiplication&division=round to least number of significant figures present.
Suppose you are playing ice hockey in the middle of a totally frictionless frozen pond. How can you move yourself to the edge of the pond ?
Sure, I can explain the rule for addition and subtraction in simple English.
The rule states that when you add or subtract numbers that have different levels of accuracy, the final answer should have the same level of accuracy as the least accurate measurement.
In the example you provided, we have two numbers to subtract: 18.56 m and 13.2 m. The least accurate measurement is 13.2 m because it only has one decimal place, while the other number has two decimal places.
According to the rule, we need to determine the rightmost significant figure, or the number that reflects the least accurate measurement. In this case, that's the digit in the tenths place.
When we subtract these two numbers, we get 5.36 m. However, since the least accurate measurement only goes to the tenths place, we need to round our answer to the same level of accuracy. So the final answer is 5.4 m.
So, the rule for addition and subtraction is to determine the least accurate measurement and use it to determine the level of accuracy in the final answer.