1. PHYZR #3:
Doing Math with Tens
Prelims – Page 4

2. We only have ten symbols to represent an infinite amount of numbers.5 7 2 8 9 6 3 1 4

3. 1 7 8 9 6 5 2 1 3 4 Problem: How do we write numbers larger than nine?2 1 3 4
“tens”
“ones”
Solution: add a new number place!

4. 2. IN BETWEEN NUMBERS
Problem: How do we write numbers in between other numbers? 1 2 3 2 1 . 4 1 3 5 2
what number is this?
“ones”
“tenths”
Solution: add a decimal place!

5. Why does this work? Every ten symbols, we have to move to a new place!
3. MULTIPLYING BY TEN , .
Get bigger by ten times (one place)
Why does this work?
Every ten symbols, we have to move to a new place!

6. Get smaller by ten times (one place)
4. DIVIDING BY TEN , .
Get smaller by ten times (one place)

7. Get bigger by ten times (one place)
3. MULTIPLYING BY TEN , .
Get bigger by ten times (one place)

8. Get smaller by ten times (one place)
4. DIVIDING BY TEN , .
Get smaller by ten times (one place)

9. Multiply by ten makes the number ______.
5. RULE SUMMARY
Multiply by ten makes the number ______.
Divide by ten makes the number ______.
bigger
smaller , .
multiply
divide
(bigger)
(smaller)

10. 6. PRACTICE , .
Solve each problem: 50
0.2 4
0.07
3.6
150
0.4
0.04

11. We’ll come back to this after we finish Page #3

12. 7. POSITIVE EXPONENTS , .
Move 3 spaces bigger.

13. 8. NEGATIVE EXPONENTS , .
Move 3 spaces smaller.

14. 9. PRACTICE , .
Solve each problem:
700
0.02
200
0.0001
0.007
8200

15. Which number is the largest?
10. WEIRD LOOKING NUMBERS
Which number is the largest? . 5 = . 5 = . = 5 = 5 . = 5 . = 5 .