File - 5th Grade Lessons

advertisement
Warm Up
• Which Standard for Mathematical Practice do
you feel is most important? Why do you think
it is the most important?
Powers of Ten
Alignment Lesson
2
20
200
2,000
• Take a look at the numbers above!!
• How are they alike?
• How are they different?
2
20
200
2,000
• Let’s use base ten pieces to model these
numbers.
2,000
200
20
2
2 x 1,000 = 2,000
2 groups of 1,000
2 x 100 = 200
2 groups of 100
2 x 10 = 20
2 groups of 10
2x1=2
2 groups of 1
2,000
200
20
2
2 x 1,000 = 2,000
2 groups of 1,000
2 x 100 = 200
2 groups of 100
2 x 10 = 20
2 groups of 10
2x1=2
2 groups of 1
•In which direction did the digit 2 move when we multiplied by 10 (instead of 1)?
•To the left, the 2 moved from the ones place to the tens place
•How many places did the 2 move in this direction?
•One place
•In which direction did the digit 2 move when we multiplied by 100 (instead of 10)?
•To the left, the 2 moved from the tens place to the hundreds place
•How many places did the 2 move in this direction?
•One place
•In which direction did the digit 2 move when we multiplied by 1,000 (instead of 100)?
•To the left, the 2 moved from the hundreds place to the thousands place
•How many places did the 2 moved in this direction?
•One place
Math Talk
Can you create a general rule or
relationship for what we’ve just
observed?
• Rule: A digit in one place represents ten times
as much as it represents in the place to its right.
-or• A digit in one place represents 1/10 of what it
represents in the place to its left.
Think about this…
• Ten of the smaller place value make one of the
next place value to the left. Therefore a digit in
one place represents ten times as much as it
represents in the place to its right. For example:
• 10 ones make 1 ten (10 units make 1 rod) so 20 is ten times
as big as 2 and the value of the 2 is ten times as much in 20
as it in 2
• The same is true for 200, 10 tens make 1 hundred (10 rods
make 1 flat) so 200 is ten times as big as 20 and the value of
the 2 in two hundred is ten times as much as it is in 20
X
3
30
300
3,000
2
2x3
=6
2 x 30
= 2 x 3 x 10
= 6 x 10
= 60
2 x 300
= 2 x 3 x 100
= 6 x 100
600
2 x 3,000
= 2 x 3 x 1,000
= 6 x 1000
= 6,000
20
20 x 3
= 2 x 10 x 3
= 6 x 10
= 60
20 x 30
= 2 x 10 x 3 x10
= 6 x 100
= 600
20 x 300
= 2 x10 x 3 x 100
= 6 x 1,000
= 6,000
20 x 3,000
= 2 x 10 x 3 x 1,000
= 6 x 10,000
= 60,000
200
200 x 3
= 2 x 100 x 3
= 6 x 100
= 600
200 x 30
= 2 x 100 x 3 x 10
= 6 x 1,000
= 6,000
200 x 300
= 2 x 100 x 3 x 100
= 6 x 10,000
= 60,000
200 x 3,000
= 2 x 100 x 3 x 1,000
= 6 x 100,000
= 600,000
2,000
2,000 x 3 =
2 x 1,000 x 3=
6 x 1,000
6,000
2,000 x 30
= 2 x 1,000 x 3 x 10
= 6 x 10,000
= 60,000
2,000 x 300
= 2 x 1,000 x 3 x 100
= 6 x 100,000
= 600,000
2,000 x 3,000
= 2 x 1,000 x 3 x 1,000
= 6 x 1,000,000
= 6,000,000
What patterns do you see in each row and column?
What general rules(s) for multiplying numbers with zeros can you
create?
Homework
Day 2, “Powers of Ten
Journal Prompt”
Download