Final answer:
Rounding to the hundredth place involves looking at the third decimal place and determining whether to round the second decimal place up or leave it unchanged. For the lengths given by Ramina, you can round to the nearest whole number or to one decimal place for estimation, which gives an easier sum to work with.
Step-by-step explanation:
The question asks about rounding a measurement to the hundredth place and finding an effective estimation strategy for adding two lengths. When rounding to the hundredth place, you look at the digit in the third decimal place, or the thousandth place. If this digit is 5 or greater, you round the hundredth place up by one. If it's less than 5, you leave the hundredth place as is.
For example, a calculator would answer 201.867 for a given calculation. Applying the rounding rule, we limit our final answer to the hundredth place. Since the digit being dropped is 7, which is greater than 5, we round up and report a final answer of 201.87.
Considering the lengths Ramina found for ribbon, 47.6 and 39.75 inches, to estimate the sum efficiently one can round both numbers to the nearest whole number or to one decimal place, depending on the desired precision. For example, 47.6 can remain the same as it has only one decimal place, and 39.75 can be rounded to 39.8, because the hundredth digit, 5, prompts the tenth digit to be rounded up. Now, adding 47.6 and 39.8 will give us an estimated sum of 87.4 inches.