Math- Week of 9/13
Monday- Introduction to powers of ten; multiplying and dividing by powers of ten.
Whole group:
Notice the patterns when multiplying by 10.
1x10= 10
10 x10= 100
10x10x10= 1,000
10x10x10x10= 10,000
Show the place value chart and explain that the value of the digit is 10 times greater each time we move
to the left. We then divide the digit by 10 each time we move to the right.
If a problem asks us to multiply a number by 10, how many places should we shift our numbers? Which
way would we move on the chart?
What if the problem asks us to multiply by 100? It is the same as multiplying 10 by another 10 which
gives us 10x10. How many places do we shift our numbers?
Talk about where to shift the numbers for division. For example, if we had; 23.5 and we wanted to
divide by 10, our 2 tens would become 2 ones, our 3 ones would become 3 tenths and our 5 tenths
would become 5 hundredths.
Complete a few practice problems as a whole group.
Go over assignments for the day.
Small group:
Review of whole group lesson; practice multiplying and dividing by powers of ten.
Go over any questions from the homework.
WednesdayWhole Group:
Review concepts from Monday.
Introduce exponents.
Remember how we can multiply
10x10= 100
10x10x10= 1,000
There is a shorter way to express this.
We can write 102 (10 to the second power)
10 is our base number and the small 2 is called an exponent.
Does anyone know what this would equal?
Do I just multiply 10 by 2 to get 20?
No, 102 means that I will multiply 2 tens together which gives us 10x10=100.
Therefore, 102 = 100
What if I wrote 103, what would the expanded form be?
10x10x10= 1,000
103= 1,000
103 is our exponential form, 10x10x10 is our expanded form and 1,000 is our standard form.
As a group, practice multiplying and dividing using exponential form.
Go over assignments for the day.
Small Group:
Review concepts and talk about exponential form.
Complete practice problems using exponential form.
For example, 34.57 multiplied by 102
Go over questions from homework.
Extension problems