Transcript Step 1

© 2007 M. Tallman
Step 1:
Circle the digit in
the place that you
must round to.
Step 2:
Draw an arrow to
the place on the
right.
Round to the nearest thousands place.
3,275
Findright
yournext
number.
Look
door.
© 2007 M. Tallman
Step 1:
Circle the digit in
the place that you
must round to.
Step 2:
Draw an arrow to
the place on the
right.
Step 3:
If the number is
four or less, then
the circled number
stays the same.
Step 4:
All numbers to the
right of the circled
number become
zeros.
Round to the nearest thousands place.
000
3,275
Just
Ignore!
2 is less
than 4
4 or less, just ignore.
© 2007 M. Tallman
Step 1:
Circle the digit in the
place that you must
round to.
Step 2:
Draw an arrow to the
place on the right.
Round to the nearest hundreds place.
8,893
Findright
yournext
number.
Look
door.
© 2007 M. Tallman
Step 1:
Circle the digit in the
place that you must
round to.
Step 2:
Draw an arrow to the
place on the right.
Step 3:
If the number is four
or less, then the
circled number stays
the same.
Step 4:
If the number is 5 or
greater then add 1 to
the circled number.
Step 5: All numbers
to the right of the
circled number
become zeros.
Round to the nearest hundreds place.
8, 8
993
00
8+1=9
9 is not
less than 4
or more,
less, just
54 or
add ignore.
1 more.
© 2007 M. Tallman
9 × 47
0
The actual
answer is 423, so
our estimation is
pretty accurate.
1
1
9 × 50 = 450
Step 1:
Rounding is
always first.
Decide which
place to round to.
Step 2:
Round 47 to
the nearest
ten.
Step 3:
“Box” and
solve the
basic math
fact.
© 2007 M. Tallman
Step 4:
Count the zeros
in both factors.
Place the zeros
in the product.
6 × 730
0
1 2
The actual
answer is 4,380,
so our estimation
is pretty
accurate.
1 2
6 × 700 = 42
, 00
Step 1:
Rounding is
always first.
Decide which
place to round to.
Step 2:
Round 730
to the
nearest
hundred.
Step 3:
“Box” and
solve the
basic math
fact.
© 2007 M. Tallman
Step 4:
Count the zeros
in both factors.
Place the zeros
in the product.
Tip: when adding
zeros to the
product, make
sure that you do
not count the
zero in 20.
Step 1:
Rounding is
always first.
Decide which
place to round to.
4 × 528
0
1 2
The actual
answer is 2,112,
so our estimation
is pretty
accurate.
1 2
4 × 500 = 20
, 00
Step 2:
Round 528
to the
nearest
hundred.
Step 3:
“Box” and
solve the
basic math
fact.
© 2007 M. Tallman
Step 4:
Count the zeros
in both factors.
Place the zeros
in the product.
$76.98 × 7
1
0
2 3
The actual
answer is
$538.86, so our
estimation is
pretty accurate.
1 2 3
$80. 00 × 7 = $560.00
Step 1:
Rounding is
always first.
Decide which
place to round to.
Step 2:
Round
$76.98 to
the nearest
ten dollar.
Step 3:
“Box” and
solve the
basic math
fact.
© 2007 M. Tallman
Step 4:
Count the zeros
in both factors.
Place the zeros
in the product.
8 × $2.19
0
1 2
The actual
answer is $17.52,
so our estimation
is pretty
accurate.
1 2
8 × $2.00 = $160
.0
Step 1:
Rounding is
always first.
Decide which
place to round to.
Step 2:
Round
$2.19 to
the nearest
dollar.
Step 3:
“Box” and
solve the
basic math
fact.
© 2007 M. Tallman
Step 4:
Count the zeros
in both factors.
Place the zeros
in the product.
Estimate each product.
1. 4 × 37
4 × 40 = 160
2. 467 × 6
500 × 6 = 3,000
3. 145 × 11
100 × 11 = 1,100
4. 7 × 5,298
7 × 5,000 = 35,000
© 2007 M. Tallman
Estimate each product.
5. 9 × 62,854
9 × 60,000 = 540,000
6. $47.90 × 9
$50.00 × 9 = $450.00
7. $6,987 × 6
$7,000 × 6 = $42,000
8. 12 × 654
12 × 700 = 8,400
© 2007 M. Tallman
Estimate each product.
5. $8.75 × 11
$9.00 × 11 = $99.00
6. $376.98 × 8
$400.00 × 8 = $3,200.00
7. 7 × 32,432
7 × 30,000 = 210,000
8. 5 × 44,987
5 × 40,000 = 200,000
© 2007 M. Tallman