One Digit Multiplication
• How do you multiply by 1- digit numbers?
One Digit Multiplication
• Use Place value and regrouping.
• Estimate
• Check to see if the product is reasonable.
One Digit Multiplication
• Each day an airline flies 9 commercial jets
from New York to London, England. Each
plane holds 293 passengers. If every seat is
taken on all flights, how many people fly on
this airline from New York to London in 1 day?
Use Place Value and Regrouping.
One Digit Multiplication
• http://www.youtube.com/watch?v=tyH_r4wMis
One Digit Multiplication
•
293 X 9 = __________
• Estimate: _____ X 9 = _____
293
9 X 3 ones = _____ones
X 9
Write the ones and regroup the tens
One Digit Multiplication
•
•
•
•
•
293
X9
7
9 X 9 tens = _____tens
Add the regrouped tens.
____tens + 2 tens = _____tens
Write the tens and the regrouped
hundreds.
One Digit Multiplication
•
293
X 9
•
•
•
•
•
9 X 2 hundreds = ____ hundreds
Add the regrouped hundreds.
______hundreds + 8 hundreds =___
hundreds
So, in 1 day, _______ passengers fly from NY to
London.
How can you tell if your answer is reasonable?
What was your estimated answer?
One Digit Multiplication
• A commercial airline makes several flight each
week from New York to Paris, France. If the
airline serves 1,978 meals on its flights each
day, how many meals are served for the entire
week?
• (Remember: Repeat the process of multiplying
and regrouping until every place value is
multiplied.)
One Digit Multiplication
• Estimate: _________ X _____ = _________
•
•
1,978
X
One Digit Multiplication
• Estimate first, then solve.
• 796
• X 8
608
X4
1925
X 7
One Digit Multiplication
• Solve for the unknown number.
• 396
• X 6
• 23__6
5,12__
X 8
_____16
8,5__6
X
7
60,03__
One Digit Multiplication
• What Is the Error?????
• The Platsville Glee Club is sending 8 of its
members to a singing contest in Cincinnati, Ohio.
The cost will be $588 per person. How much will
it cost for the entire group of 8 students to
attend?
• Both Brian and Jermaine solve the problem. Brian
says the answer is $40,074. Jermaine’s answer is
$4,604.
One Digit Multiplication
• Estimate the cost:
• A reasonable estimate is _______________
• Although Jermaine’s answer seems
reasonable, neither Brian nor Jermaine solved
the problem correctly. Find the errors in
Brian’s and Jermaine’s work. Then solve the
problem correctly.
One Digit Multiplication
• Brian
• 588
• X 8
• 40,704
Jermaine
588
X 8
4,604
• Now you solve the problem 588
•
X 8
One Digit Multiplication
• What error did Brian make?
• What error did Jermaine make?
• How could you predict that Jermaine’s answer
might be incorrect using your estimate?
One Digit Multiplication
• Textbook page 151