Transcript File

MATH UNIT 2
RECALLING
MULTIPLICATION
FACTS
4TH GRADE
Choose the best term from the box.
breaking apart product factor multiples
In the number sentence 8 x 3 = 24, 8 is a _____.
In the number sentence 2 x 6 = 12, 12 is a_____.
191 + 67 = ( 191 + 9) + 58 is an example of using
the _____ strategy.
Skip Counting
10, 12, 14, 16,
____
5, 10, 15, 20,
____
3, 6, 9, 12,
____
12, 16, 20, 24,
____
8, 16, 24, 32,
____
7, 14, 21, 28,
____
100, 80, 60,
____
13, 26, 52,
104, ____
40, 20, 10,
____
Look at each array. Circle groups of 3.
What multiplication fact does each array
represent?
Nicholas is thinking of a whole number.
He multiplies the number by 5, but the
resulting answer is less than 5.
What number is he thinking about?
2-1 Patterns for Facts
What are the patterns for multiples
of 2, 5, and 9 ?
* A MULTIPLE is the product of any two
whole numbers.
To find multiples of 2 all you need to
do is skip count by 2s.
To find multiples of 5 all you need to
do is skip count by 5s.
To find multiples of 9 all you need to
do is skip count by 9s.
Skip count to find the number that
comes next.
20,
36,
99,
1,
15,
25, 30, ____
45, 54, ____
88, 77, ____
8, 15, ____
30, 45, ____
Find the product.
* A PRODUCT is the answer to a
multiplication problem.
9x1=
3x8=
5x4=
4x2=
5x7=
2x3=
6x5=
9x7=
6x3=
0 x 12 =
9x3=
4x6=
How do you know that 13 is not
a multiple of 2?
__________________
What are all of the multiples of 2
up to 20?
Alyssa is sorting socks for her mom.
She has 9 pairs of socks. How many
socks does she have in all?
While most species of starfish have 5
arms, some species can have up to
40 arms. How many arms do 9
starfish have?
_______
How many arms would 6 starfish have?
_______
How many arms would 7 starfish have?
_______
Grace is working on her model train set.
She adds 9 pieces of track. Each
piece of track is attached with 4
screws. How many screws will she
need to attach the track?
Write the equation and solve.
Which is equal to 9 dollars and
9 nickels?
______ + ______ = $______
What is equal to 17 dollars and
12 dimes?
______ + ______ = $______
In wheelchair basketball, players use
sports chairs that have 2 large wheels
and 3 small wheels each. If there are
5 players, how many…
Large wheels? _____
Small wheels? _____
Large and Small wheels? _____
_____ + _____ = _____
Each pentagon shown below has
5 sides. How many sides are there
in all?
Strategy: skip count by 5s.
Write the equation (multiplication sentence)
_____ x _____ = _____
CHALLENGE
Can you write a 3 digit number that
when it is rounded to the nearest
ten or to the nearest hundred the
answer is the same?
2 – 2 Multiplication Properties
Multiplication Properties
How can properties help you multiply?
Commutative Property of Multiplication
means that two numbers can be
multiplied in any order and the
product will be the same.
3 Groups of 2 = 6
2 Groups of 3 = 6
Zero Property of Multiplication
Any number multiplied by zero = zero
2 groups of 0
2x0=0
Identity Property of Multiplication
The product of any number and
one is that number.
1 Group of 7
1 X 7 = 7
In a soccer tournament, Ava’s
team scored zero goals in each game.
They played a total of 6 games.
Write a multiplication sentence to show
how many goals they scored in all.
Find each product.
0x5
1x6
4x7
6x3
1x5
7x0
3x9
0x8
0x3
9x4
2x7
6x5
1x1
4x0
1x9
4x5
Taylor has 6 packages of tennis balls.
How many packages of golf balls
would Taylor need so that she has
an equal number of golf balls and
tennis balls?
TYPE OF BALL
NUMBER PER
PACKAGE
BASEBALLS
1
TENNIS BALLS
3
GOLF BALLS
6
If Brianna and three of her friends each
bought one package of baseballs, how
many baseballs do they have in all?
TYPE OF BALL
NUMBER PER
PACKAGE
BASEBALLS
1
TENNIS BALLS
3
GOLF BALLS
6
Ryan scored 4 goals in each of
3 soccer games. His friend Tyler
scored 3 goals in each of 4 soccer
games. Who scored the most goals?
Explain.
Mrs. B has 27 students in her ESOL
class. She wants to rearrange the
desks in equal groups. If the desks
are in 9 groups of 3 desks now,
what are other ways that she could
arrange the desks?
Draw different arrays to show
arrangements of 24 desks.
2-3
Use known facts:
3 and 4 as FACTORS
James is replacing the wheels on
8 skateboards. How many wheels
does he need in all?
Use the DISTRIBUTIVE PROPERTY
to break apart facts into simpler
problems.
Find 10 x 4
Break the equation apart into
(5 x 4) + (5 x 4)
So 10 x 4 = ____
or
(10 x 3) + (10 x 1)
So 10 x 4 = ____
Use breaking apart to find each product.
3x4
7x6
9x2
4x7
8x4
5x3
6x4
3x7
5x8
7x9
8x6
5x9
The manatee is an endangered sea
mammal. A mother manatee is
three times as long as her baby.
How long is the baby manatee if the
mother is 12 feet long?
John, Noah, and their dads went to
the movies. Each ticket cost $7.
They also each spent $4 on snacks.
How much money did they all spend
at the movies?
In his last basketball game, Brandon
scored 15 points. Which of the
following is NOT a possible way he
could have scored his points?
5 three-point shots
3 three-point shots
and 2 three-point
shots
3 two-point shots and 5 two-point shots and
2 one-point free
5 one-point free
throws
throws
Lauren scored 6 two-point baskets
and 6 one-point free throws. Chloe
scored 6 three-point baskets. Explain
how you know each girl scored the
same total points in the game.
A botanist is growing a four-petal
pawpaw shrub. He counted 9 flowers
on the shrub. Which uses breaking
apart to find the total number of
petals on the pawpaw?
(5x4)+(4x4)
(9x4)+(9x4)
(9+4)x(9+4)
(5+4)x(4+4)
Using Know Facts: 6, 7, and 8 as
FACTORS
Are there different ways to break
apart a fact?
Mrs. B’s class drew
a map of their town.
The map is 6 blocks
by 6 blocks. How many
square blocks are on the map?
To break these apart we could say
that 6 rows of 6 is the same as
5 rows of 6 and 1 row of 6.
So
5 x 6 = _____
Plus 1 x 6 = _____
So
6 x 6 = _____
Break them apart.
7x8
8x8
6x8
7x3
6x7
9x6
5x7
4x8
8x9
3x9
8x3
7x7
Natalie and Kayla are playing chess.
Write a multiplication sentence to find
the total number of squares on the
chessboard.
Jessica, Anna, and Victoria are taking a
hiking vacation. They traveled the
distances shown in the table. Who
walked the farthest?
HIKER
DISTANCE WALKED
JESSICA
9 MILES EACH DAY FOR 8 DAYS
ANNA
8
MILES EACH DAY FOR 4 DAYS AND
4 MILES EACH DAY FOR 8 DAYS
VICTORIA
7
MILES EACH DAY FOR 5 DAYS AND
5 MILES EACH DAY FOR 7 DAYS
Mark Twain’s name is taken from
riverboat slang. “Mark twain” means
“Mark two” for 2 fathoms. One fathom
is equal to 6 feet. How many feet
does Mark Twain’s name stand for?
2-5
Recalling Multiplication Facts
What are some strategies that can be
used to find products?
Christian visited a summer camp that
has 7 tents for the campers to stay in.
Five campers are assigned to each
tent. If all of the tents are full, how
many campers are at the camp?
Find the products.
3x8
5x4
6x6
4x7
5x5
6x7
8x6
4x4
7x9
9x3
8x8
5x3
Find the products.
8
x9
6
x6
2
x8
9
x9
7
x8
5
x6
9
x7
3
x6
4
x6
9
x6
7
x7
5
x9
Mia says that she can use the fact
3 x 6 = 18 to find 7 x 6.
Is she correct? Explain her thinking.
Dylan has 9 cases to keep CDs in.
He wants to put 8 CDs in each case.
Draw a bar diagram to find how
many CDs his cases will hold.
Hailey collects Temari balls. Temari
balls originated in China and were
brought to Japan over one thousand
years ago. Hailey arranges the balls
into 3 rows with 8 balls in each row.
What is another way she can arrange
her collection into equal groups?
Arches and Bryce Canyon are two
national parks in Utah. Bryce Canyon
is 35,835 acres in area and Arches
is 76,679 acres in area.
How many acres greater is Arches
National Park?
2-6
Draw a Picture to write an equation.
A stegosaurus was 5 times as long
as a velociraptor. If a velociraptor
was 6 feet long, how long was a
stegosaurus?
Samuel has a collection of coins, all of
which are nickels and quarters. He
has 8 nickels and three times as
many quarters.
How many quarters does he have?
How many coins does he have in all?
For the Science Fair, Ben made
a model of a microraptor, one of the
smallest dinosaurs ever discovered.
He made his model 8 inches long.
The actual dinosaur was 3 times the
length of Ben’s model. How long
was a microraptor?
Nathan read that a ceratosaurus was
5 times the length of a microvenator.
A microvenator was 4 feet long.
Use this information to write a problem
you can solve by writing an equation.
Solve.
Sydney’s recipe calls for three times
as many carrots as peas. If Sydney
uses 2 cups of peas, how many
cups of carrots will she use?
Jasmine’s recipe calls for twice
tomatoes as peppers. If she
cups of peppers. How many
tomatoes will she use in
as many
uses 4
cups of
all?
Zachary’s dog has a rectangular pen.
The length is two feet longer than the
width. The width is 8 feet. Write an
equation to find the perimeter.
What is the perimeter of the dog pen?
Julia, Morgan, and Destiny swim a relay
race. Morgan swims two more laps
than Julia. Destiny swims twice as many
laps as Julia. If Julia swims 5 laps,
how many laps did they swim all
together?
Rachel is 9 years old. Her mother is
4 times as old as she is.
Use the model to find the age of
Rachel’s mother.
9
Logan, Justin, Gabriel, and Jose are
on a four person relay race team.
They each run an equal part of an 8
mile race. Which equation could you
use to find how far each member runs?
4 + ___ = 8
4 x ___ = 8
4 + 4 + 4 + 4 = ___
2 x 2 = ___
Topic 2 TEST