Vocabulary
Multiplication is the same as what repeated operation?
Addition
3 x 1000
3,000
15 x 49
735
Stephanie thinks that a good estimate for 54 x 27 is 2000. What is a better estimate?
1,500
Zayne orders 18 packs of pencils for the school year. Each pack has 6 pencils. How many pencils does Zayne buy in all?
108 pencils
The answer to a multiplication problem is called the _______.
Product
258 x 100
25,800
783 x 19
14,877
For the problem 944 x 73, Diego came up with an estimate of 75,000. Is this an overestimate, or an underestimate? Explain why.
Overestimate; Diego multiplied 1000 x 75, and both numbers are more than the actual numbers in the problem
Honey buys 21 posters to decorate her room. Each poster costs $35. What is the total amount of money that Honey spent on posters?
$735
The two methods for finding an estimate are called ________ and ____________
Rounding and Compatible Numbers
What is the product of 4 x 106?
4,000,000
365 x 104
37,960
The product of the expression:
7.9 × 104 = 7,900
is wrong. Explain why. What was done incorrectly? (write it out)
Estimate was found, instead of actual answer.
Renee has 248 photos on her cell phone. Serenity has 16 times as many photos as Renee. How many photos does Serenity have on her cell phone?
3,968 photos
What are the two types of estimates?
Overestimates and underestimates
102 x 105
10,000,000
1159 x 47
54,473
Aleyna and Brandon are disagreeing on their math group work.
Aleyna thinks that the product of 48 x 200 will be about 100,000. Brandon thinks that the answer would be closer to 1,000,000.
Who is correct? How do you know?
Neither one of them is correct. A better estimate is 10,000. 48 is close to 50, and 50 x 200 is 10,000.
Roger, Ezra, and Malachi decide to go the movies. Upon arriving at the theater, the group decides that they also each want their own popcorn, candy, and drink. The snack bar is charging $5 for a small popcorn, $7 for a box of candy, and a slushy is $4. Kids under the age of 14 have to pay $12 for admission into the theater. Write and solve the equation(s) that can be used to find the total price for Roger, Ezra, and Malachi's tickets and movie snacks.
3 x (5+7+4+12) = $84
OR
3 x 28 = $84
What is the name of the method for recording multiplication that is said to be the shortcut for partial products?
Standard Algorithm
4 x (103 x 105)
400,000,000
2345 x 6789
15,920,205
What is the best estimate for the expression:
1921 x 67
140,000
Xavier wants to start a longstanding prank on his mom by spamming her phone with text messages. He decides that every day, he will text the phrase "67" sixty-seven times per hour, for one hour each day. If he keeps it up, how many "67"s will he text his mom in the span of sixty-seven days?
4,489 "67"s