Unit 4 Contents

To help make her estimate, Grace decided to round the numbers from the table using a number line.

1. India has 143 satellites in orbit. Grace estimated where 143 would be on the number line.
   She knew it would be between 100 and 200, so she chose these two numbers as her benchmarks. Locate the mark Grace made on the number line showing 143. How did
   you decide?
2. Is 143 closer to 100 or 200?
3. Round 143 to the nearest 100.
1. Japan has 188 satellites in orbit. Using the same two benchmarks, Grace estimated where
   188 is on the number line. Find the mark Grace made for 188 on the number line. How did
   you decide?
2. Is it closer to 100 or 200?
3. Round 188 to the nearest 100.
3. Lee Yah did not round 143 to the nearest hundred. She rounded 143 in two other ways. She used the marks on these two number lines as benchmarks to do the rounding.

Using these two number lines, give two ways to round 143.