Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
Topic 4 math yay math
Yay!!!!!!!!
Yay for 4
Topic 4
Reasonableness
Lydia has 3 boxes of balls. Each box has 28 sport balls in it. She has so many balls because her very very very rich friend gave it to her. How many balls did Lydia get in all?
90 balls
3x30=90
The number is not the exact number but is close.
It is reasonable.
20 would not be a reasonable answer.
Bye
Thank you for watching topic 4 by Lydia.
Thank you and bye.
Topic 4
The prezi was made by Lydia Huang.
The videos were made by Lydia and Lynn.
Multiplying By Multiples Of 10 And 100
Find 3x50
Think,
3x50=3x5x10
3x5=15
add one 0 after15
So,
3x50=150
USING MENTAL MATH TO MULTIPLY
Do it again
3x500
Think,
3x500=3x5x100
3x5=15
add 2 0s after 15
so,
3x500=1,500
When the product of a basic fact ends in a 0, the answer will have an extra 0
6x5=30
6x50=300
6x500=3,000
Find 3x18
Break apart 18 into 10 and 8
Think of 3x18 as
(3x10)+(3x8)
30+24
Add to find the total
30+24=54
So,
3x18=54
Multiply the thousands
1
3,212
x
5
16,060
792
x 3
264
11
Multiply the hundreds. Add any extra hundreds
Step 3
Multiply the tens. Add any extra tens. Regroup if needed.
Step 2
Multiply the ones. Regroup if needed.
Step 1
Multiplying 3-digit by 1-digit numbers
060
x
5
3,212
1
Multiply the hundreds
Topic 4
29x6
Make 29 into a 30
To do that, add a 1
Now it is 30x6
The answer is 180
Remember the 1?
Do 1x6=6
minus 6 from 180
The answer
Mental Math Another Way
Using Rounding To Estimate
Estimate 4x153 using rounding
Lydia is trying to raise a lot of money for the school so her class can have a popcicle party
4x153
Topic 4
Round 153 to 150
4x150=600
2 150s is 300. 4 150s is 600.
So,
4x153 is about 600
Lydia raised more than 500 dollars.
Her class can have a party.
Using Expanded Algorithm
Here is one way to record multiplication
10
16
6x2=12
x 2
10x2=20
Partial products
12
8
26
7
x 3
Multiply the tens. Add any extra tens.
1
Multiply the ones. Regroup if necessary.
Multiplying 2-digit by 1-digit numbers
Lydia got a delivery of 3 boxes of t-shirts. Each box has 26 t-shirts inside. How many t-shirts does Lydia have in all? Let's find out.
Step 2
Step 1
20
+
32
By Lydia Huang
Multiply Greater numbers by 1-digit numbers
Multiply the ones
1
3,212
5
x
0
5
60
1
Multiply the tens.
3,212
x
happy math
wow
Topic 4!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
yay!!!!!!!!!!!!!!!!