Multiply & Powers of 10
5.7 × 10^1
57
1.28 ÷ 10^1
0.128
Estimate: 8.46 ÷ 3
9 / 3 = 3
12.6 × 8.7
109.62
The area is 3,500
The height is 6
What is the volume?
21,000
6.7 x 10^2
670
34.78 ÷ 10^2
0.3478
Estimate: 5.23 × 7
5 x 7 = 35
9.3 × 567
5,278.1
What are the 2 formulas for volume?
What the LABEL/unit of measurement you use for volume?
B x H
L X W x H
cm/ft/in ^ 3 (CUBED)
8.9 x 10^3
8,900
What happens to the decimal when dividing by 10?
It moves one place to the left
Why do we estimate before solving multiplying/dividing by decimals?
to check if our answer is reasonable and to help us determine where the decimal point may go
6.3 ÷ 0.9
Write an equivalent problem:
Estimate:
Answer:
Write an equivalent problem: 63 / 9 = 7
Estimate: 63 / 9 = 7
Answer: 7
L = 70cm
W = 80cm
H = 90cm
V = ?
504,000 cm ^3
What happens to the decimal when we multiply by 10^5th power?
It moves 5 places to the right
Why does dividing by 10 move the decimal left?
because each digit becomes 10 times smaller
Estimate & Solve:
12.6 x 8.7
Estimate: 12 x 9 = 108
Answer: 109.62
27.8 / 3 =
Estimate:
Answer:
Estimate: 27 / 3 = 9
Answer: 9.2
A group of students measured the length of their pencils (in inches). The data is shown below:
6, 6½, 7, 6, 7½, 6½, 7, 6, 7½, 6½
What is the difference between the longest and shortest pencil?
7 - 6.5
1.5 in
What is 3.4568 x 10^6
3,456,800
0.534 / 10^4
0.0000534
Estimate & Solve:
8.46 / 3
Estimate: 9 / 3 = 3
Answer: 2.82
7.5 / .05 =
Equivalent Problem:
Answer:
Equivalent Problem: 750 / 5
Answer: 150
A group of students measured the length of their pencils (in inches). The data is shown below:
6, 6½, 7, 6, 7½, 6½, 7, 6, 7½, 6½
How many pencils are 6½ inches long?
What is the most common length?
How many pencils are longer than 7 inches?
3 pencils
6 inches and 6.5 inches
2 pencils (7½ only)