3A Mrs. Pagano

Reminders:
Wednesday, December 13th is our field trip to Queens College. Please make sure you are on time as the bus leaves promptly at 9:00 AM.
Thursday, December 14th is the Christmas Pageant.
Monday, December 18th is the Holiday Boutique. Send your money in an envelope marked with your child's name.
Your child should be studying the multiplication timestables nightly.


Math Terminologies: 
Addition Properties:

Commutative Order Property:
It doesn't make a difference which order the addends are in, the sum is always the same. Ex. 4 + 5 = 9 or 5 + 4 + 9

Associative Property:
It doesn't make a difference which way the addends are grouped, the sum is always the same. Ex. 3 + (6 + 8) =17 or ( 3 + 6) + 8 + 17.


Identity Property: Any addend plus zero is itself. Ex. 12 + 0 = 12.



ESTIMATION RULES
:
1. Decide which 2 places the number is between.
Ex. 17 is between 10 and 20 
Ex. 168 is between 100 and 200
2. Look at the place value 
before the place you are rounding to. If that digit is 5 or higher round up. If it's 4 and lower round down.
Ex. If you're rounding to the 10's look at the 1's place. 17 would round to 20
Ex. If you're rounding to the 100's place look at the 10's place. 168 would round to 200
Ex, If you're rounding to the 1000's place look at the 100's place. 1,264 would round to 1,000
3. If you're rounding two different places always round both to the lowest place. This is used when we will be estimating sums. 
Ex. 34 + 489 would be 30 + 490 = 520 In this example both places would be rounded to the tens place.
 

Period​: ​There are 2 periods: the ones and thousands. 
Place- Where a digit is in each period.
Ex. 3,987 The 9 is in the hundreds place.
Place Value- The worth of a digit in its place.
Ex. 3987 The value of the 9 is 900.
Standard Form- Regular way we write numbers everyday. 
Ex. 725
Expanded Form- This is the number written by first determining the place and then finding its value.
Ex. 700 + 20 + 5
Written Form- This is the number written in words.
Ex. Seven hundred twenty five