Estimating
Products
Give the product.
300
x 30
9 000
Give the product.
600
x 200
12 000
Give the product.
2000
x 300
60 000
Give the product.
4000
x 200
80 000
Give the product.
5000
x 500
250 000
Give the place value of the
underlined digit.
3 456
tens
Give the place value of the
underlined digit.
23 467
ten thousands
Give the place value of the
underlined digit.
98 123
hundreds
Give the place value of the
underlined digit.
78 675
thousands
Give the place value of the
underlined digit.
56 789
ones
Round to the highest place
value.
85 876 = 90 000
Round to the highest place
value.
24 987 = 20 000
Round to the highest place
value.
4 567 = 5 000
Round to the highest place
value.
7 685 = 8 000
Round to the highest place
value.
87 234 = 90 000
Study the picture.
About how many mangoes do you
think are contained in the baskets?
Present the situation.
The Young Entrepreneur’s Club of Jose
Zurbito Sr. Elementary School is selling
sampaguita garland at Php3 835 per box. If
231 box were sold at the end of a month,
about how much money did the club get?
multiplicand
3 835
x 231
multiplier
Steps in estimating products.
the multiplicand and
Step 1. Round Off Round
multiplier to the highest/greatest
place value.
3 835 → 4 000
200
x 231
Steps in estimating products.
Step 2. Multiply.
Then, multiply the
rounded numbers.
4 000
x 200
8 000
To multiply numbers with zeroes,
multiply the numbers without the
zeros first. Then, tag as many zeros as
there are in the factors to the end of
the product.
Standards for Group Activity
Criteria
5
3
Points
Earned
1
Participation Participating
Participating
Not participating
very frequently in frequently in
in discussions and/
discussions and/
discussions and/ or written work
or written work or written work
On-Task
On-task the
On-task most of Frequently offentire time
the time
task
Polite
Respectful and
Respectful and Frequently
considerate at all considerate most disrespectful and
times
of the time.
inconsiderate
TOTAL
Scoring Rubrics
Criteria
10
7
5
Voice and
Volume
Voice is clear
and loud.
Audience easily
understood.
Voice is clear.
Need to repeat
Volume is good. No and increase
need to repeat and volume.
increase the volume.
Correctness All answers are
and
correct.
accuracy
Solutions are
presented.
Some answers are
Some answers
correct. Solutions are are correct. No
presented.
solution
presented.
TOTAL
Points
Earned
Estimate the product. Complete the table.
1) 4 784 x 345
Rounded
Factors
5 000 x 300
Estimated
Product
1 500 000
1) 9 456 x 29
9 000 x 30
270 000
1) 6 545 x 45
7 000 x 50
350 000
1) 478 x 234
500 x 200
100 000
1) 4 678 x 298
5 000 x 300
1 500 000
Estimate the products by rounding to the
highest place value.
1. 4567
x 452
5000
x 500
2 500 000
3. 897
x 56
2. 7845
x 36
900
x 60
54 000
8000
x 40
320 000
Estimate the products by rounding to the
highest place value.
4. 567
x 345
600
x 300
180 000
5. 3567
x 65
4000
x 70
280 000
Estimation is useful when finding actual
products
and
solving
the
realworld problems for some reasons including
efficiency, decision making, error checking,
and resource management, hence we need
to understand how to estimate products.
In estimating products of 3- to 4-digit
numbers by 2- to 3-digit numbers…
First, we need to round-off the factors to its
highest place value.
Then, we multiply the non-zero parts.
Lastly, add as how many zeroes as there is
in the factors.
Evaluation: Estimate the products.
1. 485 → 500 2. 5 678 → 6000 3. 678 → 700
x 60 x 543 x 500
x 35 x 40
x 56
20 000
360 000
350 000
4. 568 → 600
x 67
x 70
42 000
5. 7 654 → 8000
x 876
x 900
7 200 000
Home Activity: Read and solve.
1.
Inside a rice mill, there are 125 rows of sacks of palay.
Each row has 250 sacks of palay. About how many
sacks of palay are there?
2. Thirty-four average-sized rambutan weight one
kilogram. About how many average-sized rambutan
are there in 1 483 kilograms?
3. An advertising used 6 483 Christmas lights in a giantsized Christmas tree. About how many Christmas lights
were used in 364 Christmas trees?