Transcript Objectives: • Understand and use decimal place value. • Multiply and divide by 10 and 100 and explain the effect. Vocabulary.

Objectives:
• Understand and use decimal place value.
• Multiply and divide by 10 and 100 and explain the effect.
Vocabulary
H
T
U
Multiply this number by 10
What is your answer?
H
T
U
What has happened to all of the digits?
3 tens become 3 hundreds, 5 units become 5 tens
Each digit in the number has moved one column to the left.
Th
H
T
U
What happens when we multiply by 100?
(each digit in the number moves 2 columns to the left)
Multiply each of the following numbers by 10, as they appear.
230
560
1230
400
Multiply each of the following numbers by 100, as they appear.
3500
2000
21300
34 000
T
. t
U
Divide this number by 10
What is your answer?
U
.
t
Explain what has happened to each
of the digits.
The 4 tens become 4 units, the 6 units become 6 tenths.
Each of the digits in the number has moved one column to the right.
U
. t h
What happens when we divide by 100?
Each of the digits in the number moves two columns to the right.
Divide each of the following numbers by 10, as they appear.
5.7
13.4
35.0
7.0
Divide each of the following numbers by 100, as they appear.
4.50
3.9
4.09
0.50
T1.1B
As the number is highlighted multiply or divide by powers of
10 as instructed.
400
3
30
500
1000
70
9
40
20
50
200
8
300
5
60
700
3 x 10 = 30
30
3
3x1=3
X?
X?
X?
3 x 0.1 = 0.3
0.3
3
X?
3 x 10 000 = 30 000
30000
3000
3 x 1000= 3000
X?
X?
300
3 x 100 = 300
Look carefully at this spider diagram before you move on.
Multiplication Spider Diagram
W/S1.1B
Using worksheet W/S 1.1B complete your own multiplication
spider diagram. Choose your own number in the middle.
Now check your answers using a calculator.
Try to state the answer before it appears on the spider diagram.
4.65
÷ 100
÷ 10
46.5
465
÷ 1 000
465
÷1
0.465
Division Spider Diagram
W/S 1.2B
Start with a number of your choice in the middle and
complete the division spider diagram.
Now check your answers on a calculator before you move on.
T1.2B
0.3
30
6
40
400
5
0.6
0.5
50
4
300
0.4
3
500
60
600
I divided by ten and my answer is 0.6 – what number did I start
with?
I multiplied by 100 and my answer is 40 – what number did I
start with?
Make up three questions like the ones above and try them out on
someone else – explain your working to them if necessary.
Objectives:
• Understand and use decimal place value.
• Multiply and divide by 10 and 100 and explain the effect.
Vocabulary
Thank you
for your
attention