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Lesson 1: Place Value. Unit 1: Number Sense. 12587654236841. Why is this number hard to read!?. 4 538 902 761. For the number above, find and write the digits for the following place values: ten thousands ones thousands ten millions billions hundred millions.
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Lesson 1: Place Value Unit 1: Number Sense
12587654236841 Why is this number hard to read!?
4 538 902 761 • For the number above, find and write the digits for the following place values: • ten thousands • ones • thousands • ten millions • billions • hundred millions
Take these numbers and write them with the correct spacing… • 3412 • 34125 • 864312 • 9004999 • 60548902 • 432157809 • 3412 • 34 125 • 864 312 • 9 004 999 • 60 548 902 • 432 157 809
Another student did this: • wrote 78939045672 as 789 390 456 72 • Is this right? Why or why not? • What was this student thinking? • Why did he/she make this mistake? • How to avoid this mistake: • Start at the right, draw lines in between every third digit. • ex. 78939045672 78|939|045|672 78,939,045,672
45 3890 2761 • What is the place value of the 5? • Was it harder to read the place value in the number this way? • How is this spacing different from how we usually write a number? • We usually group place values by 3’s, (ones, hundreds, thousands), so it’s weird to see it grouped in 4’s.
In Japan, however… • their place value names look like this: one ten hundred thousand man ten man hundred man thousand man oku ten oku hundred oku thousand oku chou ten chou hundred chou thousand chou • man means ten thousand (10 000) • what does oku mean?? How about chou??? • oku means 100 000, and chou means 1 000 000. • This means their place values are grouped by 4’s!!
Comparing Values of Digits • What does it mean for a number to be so many times another number? • 30 is 10 times 3, so 30 is ten times as big as 3.
How many times more is the first 3 worth than the second 3? 10 10 10 10 10 10 100 1000 10 000 100 000 100 000 100 000 • 33 • 330 • 3300 • 33 000 • 334 507 • 3 398 412 • 303 • 3003 • 30 003 • 300 003 • 342 173 • 2 356 783 542
How many times more is the 6 worth than the 3? • 63 • 630 • 6300 • 63 000 • 634 507 • 6 398 412 • 603 • 6003 • 60 003 • 600 003 • 642 173 • 2 642 173 542 • 20 • 20 • 20 • 20 • 20 • 20 • 200 • 200 • 20 000 • 200 000 • 200 000 • 200 000
How many times more is the 3 worth than the 6? • 36 • 360 • 3600 • 36 000 • 364 507 • 3 698 412 • 306 • 3006 • 30 006 • 300 006 • 342 176 • 2 342 176 542 • 5 • 5 • 5 • 5 • 5 • 5 • 50 • 500 • 5000 • 50 000 • 50 000 • 50 000