Transcript M4.A.3.1.3

M4.A.3 Compute accurately
and fluently and make
reasonable estimates.
M4.A.3.1 Apply rounding and/or
estimation strategies to solve
problems.
M4.A.3.1 Eligible Content
• M4.A.3.1.1 Round whole numbers to
the nearest ten, hundred, thousand,
ten-thousand or hundred-thousand
• M4.A.3.1.2 Round amounts of money
to the nearest dollar.
• M4.A.3.1.3 Estimate the answer to addition,
subtraction and multiplication problems
using whole numbers through 6 digits (for
multiplication, no more than 2 digits X 1 digit,
excluding powers of 10).
• M4.A.3.1.1 Round whole numbers to
the nearest ten, hundred, thousand,
ten-thousand or hundred-thousand
• M4.A.3.1.2 Round amounts of money
to the nearest dollar.
PSSA Sample Items
Rounding
Use rounding
• When the question asks you
to estimate.
• When the question asks
“about how many”…?
• When an exact answer isn’t
possible.
• When an answer is difficult
to obtain.
Memorize this Poem
Find your number.
Look right next door.
4 or less just ignore.
5 or more, add 1 more.
Round this number to the nearest
ten thousand.
Find your number.
3 6 8,9 7 1
Circle the number in the ten
thousands place.
Round this number to the nearest
ten thousand.
Look right next door.
3 6 8,9 7 1
Draw an arrow to the right of the
number.
Round this number to the nearest
ten thousand.
4 or less, just ignore.
3 6 8,9 7 1
8 is larger than 4 so go to the next
line of the poem.
Round this number to the nearest
ten thousand.
5 or more, add 1 more.
+1
3 6 8,9 7 1
Add 1 to the 6.
Round this number to the nearest
ten thousand.
5 or more, add 1 more.
3 7 0,0 0 0
Add 1 to the 6 and all the numbers
to the right of the 7 become 0’s.
The Answer
368,971 rounded to the
nearest ten thousand is
3 7 0,0 0 0
Round this number to the nearest
thousand.
Find your number.
3 5, 3 2 7
Circle the number in the thousands
place.
Round this number to the nearest
thousand.
Look right next door.
3 5, 3 2 7
Draw an arrow to the right of the
number.
Round this number to the nearest
thousand.
4 or less, just ignore.
3 5, 3 2 7
Since 3 is less than 4 we do not change
the 5.
Round this number to the nearest
thousand.
4 or less, just ignore.
3 5, 0 0 0
Change the numbers to left of 5 to 0’s.
The Answer
35,327 rounded to the
nearest thousand is
3 5, 0 0 0
Round this number to the nearest
dollar.
Find your number.
$ 5. 8 7
Circle the number where the dollars
are.
Round this number to the nearest
dollar.
Look right next door.
$ 5. 8 7
Draw an arrow to the right of the
circled number.
Round this number to the nearest
dollar.
4 or less, just ignore.
$ 5. 8 7
8 is greater than 4 so go to the next
line of the poem.
Round this number to the nearest
dollar.
5 or more, add 1 more.
+1
$ 5. 8 7
Since 8 is greater than 5 add 1 to the
5.
Round this number to the nearest
dollar.
5 or more, add 1 more.
$ 6. 0 0
Change the 5 to a 6 and change all the
numbers to the right to 0’s.
The Answer
$5.87 rounded to the
nearest dollar is
$ 6. 0 0
Practice Rounding
Round to the Nearest Hundred
a.
b.
c.
d.
e.
f.
g.
h.
i.
478
696
233
713
485
778
452
305
841
a.
b.
c.
d.
e.
f.
g.
h.
i.
500
700
200
700
500
800
500
300
800
Round to the Nearest Thousand
a.
b.
c.
d.
e.
f.
g.
h.
i.
1,715
5,475
6,562
3,470
9,025
5,789
8,543
4,007
2,800
a.
b.
c.
d.
e.
f.
g.
h.
i.
2,000
5,000
7,000
3,000
9,000
6,000
9,000
4,000
3,000
Round to the Nearest Ten Thousand
a.
b.
c.
d.
e.
f.
g.
h.
i.
48,253
61,744
54,769
35,535
48,600
70,209
15,437
49,036
68,703
a.
b.
c.
d.
e.
f.
g.
h.
i.
50,000
60,000
50,000
40,000
50,000
70,000
20,000
50,000
70,000
Round to the Nearest
Hundred Thousand
a.
b.
c.
d.
e.
f.
g.
h.
i.
516,573
430,001
112,786
807,921
576,439
156,748
856,125
239,875
186,093
a.
b.
c.
d.
e.
f.
g.
h.
i.
500,000
400,000
100,000
800,000
600,000
200,000
900,000
200,000
200,000
Rounding Money
Word Problems
• Mary bought two boxes of crackers for
$0.99 each and a pound of grapes for
$1.29. About how much did she spend?
• About $3.00
• Martin has 4 quarters and 2 dimes. About
how much money does he have?
• $1.00
• At the taco stand, Jaleel bought a taco for
$2.75 and a drink for $0.95. About how
much did he spend?
• $3.00
• M4.A.3.1.3 Estimate the answer to
addition, subtraction and multiplication
problems using whole numbers through 6
digits (for multiplication, no more than 2
digits X 1 digit, excluding powers of 10).
PSSA Sample Item
PSSA Sample Item
PSSA Sample Item
Estimating the Answer
• Estimates are not exact numbers. To
identify estimates, look for numbers that
have been rounded, or look for clues such
as almost, over, or about.
Exact Numbers or Estimates?
Example
•
Mount Rushmore National Memorial, the
famous sculpture of 4 American presidents,
was started in 1927. It was finished 14 years
later and cost almost $1,000,000.00 to make!
Mount Rushmore is over 5,500 ft. high. Each
head is about 60 ft. tall.
1. In what year was the sculpture started?
2. How tall is each president’s head?
3. How many presidents are on Mount
Rushmore?
Refer to the paragraph about
Mount Rushmore
4. Is the year 1927 an exact number or an
estimate? How do you know?
5. Is it correct to say that the sculpture cost
exactly $1,000,000.00 to make? Why or why
not?
6. In what year was the sculpture completed? Is
your answer an exact answer or an estimate?
7. Why is it important to know if numbers are
exact or if they are estimates?
Answer each question. Give a reason for your
choice.
Mount Rushmore National Memorial is off
Highway 244 and is about 25 miles from
Rapid City, South Dakota. The memorial is
open 24 hours a day. Each year, more than
2,500,000 people come to view the sculpture.
1. Which number below is used as an estimate?
a. 2,500,000 visitors
b. Highway 244
c. 24 hours a day
2. Which number below is used as an exact
number?
a. 2,500,000 visitors
b. 25 miles
c. 24 hours a day
3. How many miles is Mount Rushmore from
Rapid City?
a. exactly 25 miles
b. about 25 miles
c. 244 miles
Estimate by rounding to the
greatest place value
a.
b.
c.
d.
e.
f.
g.
h.
i.
32 + 27 =
52 – 37 =
86 – 43 =
763 – 214 =
3,564 + 758 =
7,638 + 3,879 =
2,375 + 4,680 =
24,316 + 13,452 =
47,865 + 26, 527 =
a.
b.
c.
d.
e.
f.
g.
h.
i.
60
10
50
600
3,000
10,000
7,000
30,000
80,000