Transcript and add the carried-over amount. Anything to carry

5-Minute Check
•Multiply.
•2 x 44
•4 x 39
•3 x $21
•5 x 89
•A truck weighs twice as heavy as a
car. The car weighs 3,000 pounds.
How much does the truck weigh?
Multiply Multi-Digit Numbers
(even across zeros)
Objective
 By the end of the lesson, you will be
able to multiply a three-digit and a
four-digit number by a one-digit
number.
 Standard 4NS3.2 - Demonstrate an
understanding of, and the ability to
use, standard algorithms for
multiplying a multidigit number by
a two-digit number and for dividing
a multidigit number by a one-digit
Introduce
 Let’s look at a problem:
1, 124
x3
• How many ones are in 1,124?
• Multiply the ones by the 3. What is the product? Should we
carry over?
• Multiply the tens. What is the product? Should we carry over
any?
• Multiply the hundreds. What is the product? Should we carry
over?
Example
• Today is Anna’s birthday, and she is nine years old.
There are 365 days in one year. How many days old
is Anna?
• You multiply multi-digit numbers the same way you
multiply a two-digit number by a one-digit number.
• 365
x9
First, multiply the 9 by 5. Anything to carry over?
Next, multiply the 9 by the 6 (tens) and add the
carried-over amount. Anything to carry over?
Then, multiply the 9 by the 3 (hundreds) and add the
LET”S LISTEN!!
• Let’s hear from Mrs. Verughese about
multiplying money using four-digit by
one-digit.
• Mrs. Verughese!!
• Let’s listen to Mr. Parsons as he explains
another problem with a zero as one of the
digits.
• Mr. Parsons!!
Teach
• Let’s look at a problem that has a zero in it:
• 1,104
x3
• How many ones are in 1,104? Multiply the ones by 3.
What is the product? Anything to carry over?
• How many tens are in 1,104? What is the product of any
number and zero? Then, add the carried over amount.
Anything to carry over?
• Multiply the hundreds. What is the product? Anything to
carry over?
• Multiply the thousands. What is the product? Add the
Bales Bucks
Multiply. Check for
reasonableness.
135 x 2
532 x 6
$2,957 x 3
7,832 x 7
Multiply. Check for
reasonableness by
estimating the
products.
303 x 3
$507 x 6
908 x 8
2,007 x 8
Assignment
Page 280 - #’s 7 – 12
Page 286 - #’s 9 - 15
Get them all correct – No Math
Homework