Powers of 10
27 x 106
27,000,000
Estimate the product. Hint: remember to round to the highest place value.
42 x 598
40 x 600 = 24,000
Find the product.
51 x 10
510
A tool used to help solve problems
What does it mean to overestimate or underestimate?
Overestimate - an estimate that is greater than the actual value
Under estimate - an estimate that is lesser than the actual value.
Please write using exponents
29 x 10,000
29 x 104
Estimate the product.
25 x 191
30 x 200 = 5,000
Find the product.
439 x 22
9,658
Use a bar model to show: A had wire store ordered 13 packs of nails from a supplier. Each pack contains 155 nails.
Bonus 100: How many nails did the store order?
Check and discuss.
2,015 nails
What is a variable?
A letter that represents a number in an expression or equation.
Please find the product.
52 x 105
5,200,000
Estimate the product. Is the estimation over or under?
380 x 690
Bonus 100: How do you know?
400 x 700 = 280,000
Over
Both numbers are being rounded up.
505 x 77
38,885
An aquarium has display tanks that each contain 175 fish. How many fish are on display in 6 tanks? Please show a bar graph.
1,050 fish
How do I know if I am underestimating or overestimating?
Rounding more down than up will result in underestimating, round more up than down will result in overestimating.
Which expression is greater?
93 x 103 or 11 x 104
How do you know?
11 x 104;
93,000 < 110,000
The decimal is more place values, making the number greater.
Create your own problem that you would want to over estimate.
Check and discuss
108 x 58
6,264
Jerry weighs 105 pounds. If a male brown bear weighs 11 times as much, what is the brown bear's weight? Draw a bar diagram and write the equation.
1,155 pounds
Create a problem that has partial products. Then solve your problem.
Check and discuss briefly
Create your own power of 10 and provide the solution. The given number must be in the hundreds or higher, and the power of 10 must be 3 or more.
Check given problem.
Samuel needs to estimate the product of 23 x 395. Explain 2 different methods Samuel could use.
Compatible numbers
Find the product. Estimate to check for reasonableness. Explain.
520 x 63
32,760
500 x 60 = 30,000
It is reasonable because the estimation and the actual product are not too far off.
If the teacher brought pizza for your class, and each student got 3 pieces, how many pieces of pizza would you need? Draw a bar diagram. Hint: How many students are here today?
Check and discuss.
Create a problem including a variable. Then solve.
Check and discuss