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Mathematics IVMichael Carl S.R. Divinaflor
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Drill: Basic addition facts
a. 9+7=
b. 8+3=
c. 7+5=d. 9+4=
e. 8+6=
f. 7+9=
g. 4+7=
h. 6+5=i. 8+5=
j. 9+6=
16
11
1213
14
16
11
1113
15
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Review:
How do you round off numbers?
Try this!
a. Hundred thousands
b. Ten thousands
c. Thousands
564,789
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Check this:
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Read:Mang Mario has a coconut plantation.
He usually works in his farm the whole day.He Harvested 11, 389
coconuts on the first
month and 15,481 on the second month.
About how many coconuts did he harvest?Q1: What is asked?
The estimated number
of coconuts he harvested.
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Read:Mang Mario has a coconut plantation.
He usually works in his farm the whole day.He Harvested 11, 389
coconuts on the first
month and 15,481 on the second month.
About how many coconuts did he harvest?Q2: What are the
given?
11, 389 coconuts on the first month
and 15,481 on the second month
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Read:Mang Mario has a coconut plantation.
He usually works in his farm the whole day.He Harvested 11, 389
coconuts on the first
month and 15,481 on the second month.
About how many coconuts did he harvest?Q3: What is the operation
to be used?
addition
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Read:Mang Mario has a coconut plantation.
He usually works in his farm the whole day.He Harvested 11, 389
coconuts on the first
month and 15,481 on the second month.
About how many coconuts did he harvest?Q4: What is the number
sentence?
11, 389 + 15, 481=N
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11 389
+ 15481
10
0002000030
000
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Activity:Work with a partner. One will get the exact
sum and the other will estimate the sum tothe highest place
value.a. 594
+678
b.3,978
+5,697
c.5,928
+1,436
d.763
+492
e.1,397
+1,280
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Generalization:
In estimating the sums of 6 or
more digit addends, round theaddends to the nearest highest
place value then add.
A good estimate is a little lessof more than the exact
number.
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Solve:
Mrs. Dayos poultry farmproduced 236 378 eggs in 1997 and
147 932 eggs in 1998. About how
many hundred thousands of eggswere produced in two years?
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Evaluation:Round each addend to the highest place
value. Then add.1. 713 156
+ 291 724
5. 192 143
+ 361 414
2. 138 819
+ 861 412
3. 514 912
+ 813 125
4. 614 346
+ 201 223
1 000 000 1 000 000 1 300 000
800 000 600 000
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Assignment:
Answer Practice Your Skills numbers
1-10. Page 22 of your workbook.
