Transcript Lesson 16 - GEOCITIES.ws

Lesson 16
Solving Problems With Measures
Example 1
 Jeff cut a string 4 feet long into three
equal pieces. How long are the pieces?
 Strategy: Change to another unit if
necessary.
 Step 1: Decide what operation will solve
the problem. Use division, since you
have to divide the string.
 Step 2: Notice that you cannot divide 4
feet by 3 evenly. If the string were 3 feet
or 6 feet long, then you could divide the
number evenly by 3 (it may be ok to
have a mixed number for an answer).
 Step 3: Use the Customary
Measurement table, if you don’t know
the conversion factor, found in Lesson
29, the back of your text, or in your
planner, to convert feet to inches. 1 foot
= 12 inches so 4 feet = 4 x 12 = 48
inches.
 Step 4: Divide the number of inches by
3. 48 inches / 3 = 16 inches.
Solution
 Each piece of string is 16 inches long (or
1 foot 4 inches long). It can also be
1 1/3 feet long.
Example 2
 Manny brought 8 packages to the post
office. Each weighed 3 pounds 7
ounces. How much did the packages
weigh all together?
 Strategy: Use the conversion tables if
necessary.
 Step 1: Decide what operation will solve
the problem. Use multiplication, since
you want to find the total weight.
 Step 2: Do the math – multiply pounds
and ounces separately. 3 lb. X 8 = 24 lb.;
7 oz. X 8 = 56 oz.
 Step 3: Use the Customary
Measurement conversion table to
convert ounces to pounds if you do not
know the conversion factor. 16 oz. = 1
lb. So, 56 oz. / 16 = 3 lb. 8 oz.
 Step 4 Add the pounds together from
Steps 2 and 3.
24 lb. + 3lb. = 27 lb.
Step 5: Add the ounces.
Solution
 The packages weighed 27 lb. 8 oz.
 Tip: Converting to the smaller unit of
measure will make solving the problem
easier.
Example 3
 The temperature outside of Clara’s
classroom on Monday at noon is 15C.
The next morning the temperature went
down 18 degrees. What was the
temperature the next day?
 Strategy: Subtract 18 degrees or add 18 degrees. Use a number line if you
need to show the problem.
 Step 1: 15 – 18 = or 15 + (-18) = -3
Solution
 The temperature was -3 or 3 below 0
the next day.