Transcript adding and subtracting decimals

Warm Up *have work from test moz on desk
• Practice : 0.35 + 0.25 with base 10 blocks
1) You have 2 ropes that are 1.15 feet and 2.06 feet. Together how long are
they?
• Practice : 0.85 – 0.25 with base 10 blocks
2) You have a rope that is 1.54 feet and you cut off 0.15 feet. How much rope
is left?
Warm Up
• Practice 0.5 + 0.25 with a number line
1) I have 1.5 oz of peanut butter left in a jar. I combine it with another jar that
has 2.25 oz of peanut butter. How much peanut butter do I have now?
• Practice 2.5 – 0.25 with a number line
2) I have 3.5 laps to run in P.E. and I have already run 1.25 laps. How many laps
do I still need to run?
Announcements
• Homework
• Testmoz quiz (addition and subtraction of decimals)
• Weekly Math #16 (due tomorrow)
• Weekly Math #17 (due Friday)
Remind 101
• TO: 704-815-6025
• TEXT THIS: @b2615
Review Adding Decimals steps EX: 13.009 +12.83
• Step 1 :
• Estimate 1st
• Step 2 :
• Line up decimals
• Step 2b :
• Insert zeroes as placeholders (not required, but helpful)
• Step 3 :
• Add
• Step 4 :
• Check with estimate
Subtracting Decimals
• Step 1 :
• Step 2 :
Estimate 1st!
Line up decimal points (1st # on top)
• Step 2b :
• Step 3 :
• Step 4 :
Ex: 10.508 – 6.73 – TEST MOZ
Insert zeroes as placeholders (not necessary, but helpful)
Subtract
Check with estimate
STRETCH BREAK
Zee wants to make 2 liters of pink lemonade for a party.
She squeezed the eight lemons she had and got 0.375
liters of lemon juice. She had 0.35 liters of cranberry
juice, and 1.2 liters of water.
How much lemonade can she make? How much more or
less than 2 liters will she have?
• Estimate
• Convert these different amounts into thousandths
• Find the sum of the total amount of lemonade using expanded form.
• Find the difference between the sum and 2 liters using expanded form.
• Compare with estimate
Maura is going on a plane. She can’t have a carryon
backpack that weighs more than 10 pounds. She weighed
the items she wants to pack on a sensitive scale: book
5.142 pounds, jacket 3.6 pounds, backpack 1.28 pounds.
What is the total weight of these items?
• Find the sum
• Does Maura’s backpack weigh less than 10 pounds?
Practice - Adding
1) Aaron’s family has several gold items they want to melt
down to make a gold bar. There is a spoon that weighs
124.414 grams, a broken necklace that weighs 108.86
grams, and an earring that weighs 15.5 grams. How much
is the total weight of gold they have?
2) Nicky is trying to drink 2.5 liters of water a day. She drank
0.878 liters after breakfast, 1.2 liters after lunch, and 0.75
liters before dinner. How much did she drink all together?
STRETCH BREAK
Walter wanted to compare the great pitcher Walter
Johnson’s earned run average to other great pitchers to find
out how much lower it was. A lower ERA is better than a
higher ERA. He found these pitchers’ lifetime ERA statistics.
Walter Johnson 2.167
Sandy Koufax 2.76
• Estimate
• How is subtracting decimals similar to adding decimals?
• Why is it important to pay attention to 0 during subtraction?
• How much better was Walter Johnson’s ERA than Sandy Koufax’s?
Practice - Subtracting
1) Sandy Koufax has a 0.655 win/loss percentage; Walter
Johnson’s is 0.599. How much higher is Koufax’s win/loss
percentage than Johnson’s?
2) Pam needs to take 4.5 milliliters of cough syrup, but only
has 2.745 milliliters. How much more does she need for a
full dose?
Practice – Adding & Subtracting
1) Alex’s family went on a hike at Mt. Rainier National Park in Washington.
The Silver Falls Trail is a total of 3.1 miles. They hiked 1.534 miles and
reached Silver Falls. How much farther do they have to hike to complete
the trail?
2) A cheetah can run 112.654 kilometers per hour. A pronghorn antelope
can run 98.17 kilometers per hour. How much faster is the cheetah than
the antelope?
3) Becky wanted to grow out her hair. She measured the growth each
month. The first month her hair grew 1.775 centimeters. The next month
it grew 1.45 centimeters. The third month it grew 1.0625 centimeters.
The fourth month it grew 0.875 inches How many centimeters did her
hair grow in the four months?
4) On a field trip, a 6th grade class traveled 19.955 kilometers by train, 7
kilometers by bus, and 2.3 kilometers by car. How far did they travel all
together?
Work on Test Corrections
• Bring me your 3 guided notes (+,-, and +/-)
• When finished work on Weekly Math #16 and #17