Estimating
Multiplying by 10,100, and 1,000
Decimal Placing
Multiplying with whole numbers and two decimals
Potpourri from Topic 6
100
Estimate - 15.3 X 3
What is 15 X 3 = 45?
100
Compute 58 X 10 = 58 X 100 = 58 X 1,000 =
What are 580, 5,800, and 58,000?
100
In the problem, 5 X 3.4 = 17, this is where the decimal point belongs.
What is 17.0?
100
A gymnast gets a score of 4.85 on her first event. If she gets the same score on all her four events this is her final score.
4.85 X 4. What is 19.4? or 19.40.
100
Draw a model for 0.15 X 3 using longs and cubes. Hint - 0.15 = 0.1 + 0.05. Longs are 0.1
What is (_ _ _ _ _ _ _ _ _ _) _ _ _ _ _ (_ _ _ _ _ _ _ _ _ _) _ _ _ _ _ (_ _ _ _ _ _ _ _ _ _) _ _ _ _ _
200
A video game controller costs 26.85. If you are going to buy three controllers to play with this the BEST estimate.
What is 30 X 3 = 90?
200
Compute 10^1 = 10^2 = 10^3 =
What is 10, 100, and 1,000
200
In the problem, 6 X 5.01= 3006, this is where the decimal point belongs.
What is 30.06?
200
34 X 5.3
What is 180.2?
200
0.06 X 10^2
What is 6?
300
Estimate and compute. 25.07 X 0.48 =
What is 25 X 0.5 = 12.5?
300
This is the product of 0.56 X 10^3
0.56 X 1,000 = 560.0
300
In the problem, 0.9 X 0.9 = 81, this is where the decimal point belongs.
What is 0.81?
300
Compute - 405 X 0.47 =
What is 190.35?
300
Derek's basketball team drank 20.5 bottles of Orange Drink after the game. Each bottle contained 0.5 liters of Orange Drink. How many liters did they drink in all. Place the decimal. Show why you chose that place. 20.5 X 0.5=1025
What is 20.5 X 0.5 = 10.25 If you estimate 20 X 0.5 = 10. Also when multiplying you have two numbers to the right of the decimal point so your product will move the decimal two places.
400
Choose the best estimate - 59.16 X 0.19
What is A 100 X 0.15 = 15 B 60 X 0.2 = 12 C 60 X 0.1 = 6 D 70 X 0.2 = 14
400
5.1 X 100
What is 510?
400
Jordan's calculator can perform computations but it won't show the decimal point. He enters 3.04 X 6.04 and he gets the answer 183616. This is where he should put the decimal point.
What is 18.3616?
400
Compute 3.8 X 2.57
What is 9.766?
400
Estimate 308 X 0.28. Which method did you choose and why did it work? Hint - Compatible numbers or rounding.
What is 300 X 0.30 = 90 or 300 X 0.50 = 150?
500
Each T-shirt costs $12.85. Pat has $55. Does he have enough to buy 4 T-shirts?
What is Yes? 12 X 4 = 48 or 13 X 4 = 52?
500
0.46 X 10^3
What is 0.46 X 1,000 = 460?
500
This is why 2 is not a good estimate for 13.68 X 0.04.
What is estimating 13.68 X 0.04 is 14 X 0 = 0. The product should be close to, but not zero. Two is too high because 0.04 is very close to zero.
500
Lindsay is on vacation for 3.5 days. While she is gone she pays a dog sitter 25.50 per day to take care of her puppy. This is the amount she will pay the dog sitter during her vacation. Write an equation and solve.
What is 3.5 X $25.50 = $89.25?
500
At Jimmy's Pizza a turkey sandwich costs $4.75. Ham and Cheese cost $2.95. If Tyrese buys 5 turkey sandwiches and ham sandwiches this is how much he pays in total for all the sandwiches.
What is 23.75 + 14.75 = 38.50?