MATHTIME Week 1 Day 4

DRILL

Read the following numbers.

18 453

9 009 370

5 702 045

4 901 067

Guessing GameAll pupils will solve the given problem as fast as they can. The first pupil who will give the correct answer wins.a. My ones digit is 2. My tens digit is twice the ones digit. My hundreds digit is thrice the ones digit and my thousands digit is the sum of the ones and the tens digit. What number am I?b. I am a 6-digit number. My thousands digit is 9. My ten thousands digit is 4.My hundred thousands digit is 3. My hundreds digit is 2.My ones digit is 7. The other digits is zero. Who am I?

REVIEW

A. If we skip count by 100s1 238 is nearer to 1 200 than 1 300.4 299 is nearer to ____ than ______.5 478 is nearer to ____ than ______.6 872 is nearer to ____ than ______.2 879 is nearer to ____ than ______.4 590 is nearer to ____ than ______.

B. If we skip count by 1 000s41 238 is nearer to 41 000 than 42 000.52 299 is nearer to ______ than ______.75 475 is nearer to ______ than ______.16 872 is nearer to ______ than ______.32 479 is nearer to ______ than ______.47 590 is nearer to ______ than ______.

MOTIVATION

PRESENTATION

How will you solve the problem?

Performingthe Activities

To what number is 22 950 closer? 20 000 or 30 000? Since it is closer to 20 000, round it down.Find 25 800. Where is it located? Look at the number line. Examine. Lead pupils to answer the problem by asking: Which is 25 800 closer to?

Study the number line.

When do we round up and when do we round down?

Group ActivityComplete the table.

MONEY Round to the Nearest Ten Thousands Hundred Thousands Millions

Php 5 016 575 Php 7 867 570 Php 1 265 420 Php 8 704 765 Php 3 897 543

Processingthe Activities

When do we round up and when do we round down?

Reinforcing the Concept

and Skill

Round off the following numbers to the indicated place value. Nearest Thousands 1) 78 125 _________________2) 51 789 _________________3) 25 507 _________________4) 6 895 _________________5) 27 023 _________________

Round off the following numbers to the indicated place value. Nearest Ten Thousands 1) 781 000 _________________2) 2 342 670 _________________3) 54 671 _________________4) 63 421 _________________5) 241 584 _________________

Round off the following numbers to the indicated place value. Nearest Hundred Thousands

1) 8 562 902 _________________2) 5 124 900 _________________3) 12 578 124 _________________4) 9 876 540 _________________5) 567 810 _________________

Round off the following numbers to the indicated place value. Nearest Millions 1) 14 568 140 _________________2) 29 128 035 _________________3) 50 671 904 _________________4) 47 132 090 _________________5) 1 452 907 _________________

“How do we round numbers? To round off a whole number to a specified place value, determine the digit to the right of the place you are rounding off to. If the digit is 5,6,7,8,and 9, round it up or simply add 1 to the digit in the specified place and replace the digits to the right with zeros. If the digit is less than 5 (4,3,2,1,and 0)retain the digits in the specified place and replace/change the digits to the right with zeros

Applying to New and

Other Situations

ASSESSMENT

Round to the highest place value.1. 24 567 __________________

2. 129 467 __________________3. 72 560 458 __________________ 4. 4 670 138 __________________5. 2 453 760 435 __________________

6. 4 125 902 567 __________________7. 136 786 __________________

8. 34 089 457 __________________9. 5 246 790 653 __________________

10. 198 134 __________________

HOMEACTIVITY

Encircle the numbers that can be rounded to the given numbers.

1) 3 200 000 3 234 567 3 256 418 3 178 982 3 214 675 3 265 109

2) 47 000 000 46 864 125 47 432 160 47 876 523 47 082 971 46 087 542

3) 2 000 000 000 2 123 456 789 2 564 768 980 2 098 765 432 1 765 000 982 1 980 701 673

Enrichment

The following are the land areas in square kilometres of some Asian countries. Round off each area to one-digit accuracy. Example: 685 rounded to one-digit accuracy is 700.1. Indonesia : 1 919 443________________________2. Philippines : 300 076________________________3. Singapore : 618 ________________________4. Malaysia : 131 587 ________________________5. Brunei : 5 765 ________________________6. Japan : 377 801 ________________________7. Thailand : 513 998 ________________________8. Kampuchea : 181 035________________________9. China : 9 571 900 ________________________10. Vietnam : 329 465 ________________________