EXAMPLE 2 Solving a Problem Junior Iditarod Race In the 2001 Junior Iditarod race, one team completed the race in about 18 hours over two days. The team’s average rate was miles per hour. About how long was the race? Round to the nearest mile.
EXAMPLE 2 Solving a Problem Use the formula Distance = Rate Time SOLUTION
EXAMPLE 2 Solving a Problem Use the formula Distance = Rate Time SOLUTION
EXAMPLE 2 Solving a Problem Use the formula Distance = Rate Time SOLUTION Place the decimal point before dropping any zeroes
EXAMPLE 2 Solving a Problem Use the formula Distance = Rate Time SOLUTION Place the decimal point before dropping any zeroes ANSWER The race was about 150 miles long.
EXAMPLE 3 Checking for Reasonableness Use estimation to check that the answer to Example 2 is reasonable.
EXAMPLE 3 Checking for Reasonableness Use estimation to check that the answer to Example 2 is reasonable. Distance =
EXAMPLE 3 Checking for Reasonableness Round to its leading digit. Use estimation to check that the answer to Example 2 is reasonable. Distance =
EXAMPLE 3 Checking for Reasonableness Round to its leading digit. Use estimation to check that the answer to Example 2 is reasonable. Distance = = 144
EXAMPLE 3 Checking for Reasonableness Round to its leading digit. Use estimation to check that the answer to Example 2 is reasonable. Distance = = 144 ANSWER Because 150 is close to 144, the distance is reasonable.
GUIDED PRACTICE for Example 2 and 3 Find the product
GUIDED PRACTICE for Example 2 and 3 Find the product = 45
GUIDED PRACTICE for Example 2 and 3 Find the product =
GUIDED PRACTICE for Example 2 and 3 Find the product = = 12.04
GUIDED PRACTICE for Example 2 and 3 Find the product = =
GUIDED PRACTICE for Example 2 and 3 Find the product = = = 235.5
GUIDED PRACTICE for Example 2 and 3 Bicycle Race You complete the first leg of a bike race in about 12 hours over two days. Your cyclometer shows that your average speed for this leg was miles per hour. About how long was this leg of the race?
GUIDED PRACTICE for Example 2 and 3 Bicycle Race You complete the first leg of a bike race in about 12 hours over two days. Your cyclometer shows that your average speed for this leg was miles per hour. About how long was this leg of the race? ANSWERAbout 192 miles
GUIDED PRACTICE for Example 2 and 3 Use estimation to check whether the answer is reasonable ;
GUIDED PRACTICE for Example 2 and 3 Use estimation to check whether the answer is reasonable ; The answer is reasonable.
GUIDED PRACTICE for Example 2 and 3 Use estimation to check whether the answer is reasonable ; The answer is reasonable ;
GUIDED PRACTICE for Example 2 and 3 Use estimation to check whether the answer is reasonable ; The answer is reasonable ; The answer is not reasonable.
GUIDED PRACTICE for Example 2 and 3 Use estimation to check whether the answer is reasonable ; The answer is reasonable ; The answer is not reasonable ;
GUIDED PRACTICE for Example 2 and 3 Use estimation to check whether the answer is reasonable ; The answer is reasonable ; The answer is not reasonable ; The answer is reasonable.
GUIDED PRACTICE for Example 2 and Explain why the answer 84 is not reasonable for the product