Elementary School Lessons

Notes #15

In adding numbers without regrouping, add the digits in the ones place first, then the digits in the tens place next.

Notes #16

In adding numbers with regrouping, sums of 10 or more are renamed or regrouped to the next higher place.

Notes #14

Zero Property of Addition: any number added to zero is always equal to the same number.

Commutative Property of Addition: changing the order of the addends does not change the sum.

Associative property of addition: Changing the grouping of the addends does not change the sum.

Notes #12

Numbers that end in 0, 2, 4, 6, 8 are called even numbers.

Numbers that end in 1, 3, 5, 7, 9 are called odd numbers.

Notes #13

Addition is the process of combining of putting things together.

The addends are numbers that we put together.

The sum or the total is the answer in addition.

The symbol for addition is the plus (+) sign.

Notes #10

We can order numbers from the least to the greatest.

3, 7, 17, 36, 68

We can order numbers from the greatest to the least.

74, 52, 29, 18, 5

 

Notes #11

Ordinal numbers tell us the order or positions of objects in a given arrangement.

First

Second

Third

Fourth

Fifth

Sixth

Seventh

Eighth

Ninth

Tenth

Notes #8

A two-digit number has digits in the tens and ones places.

In a place value chart, the place value on the left is the tens and the place value on the right is the ones.

Notes #9

We use > for greater than.

We use < for lesser than.

We use = for two number with the same value.

Notes #6

Counting up to 100 is just adding one more to each number to get the next number until one reaches a hundred.

Notes #7

Skip counting by 2s: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20

Skip counting by 3s: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30

Skip counting by 5s: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50

Skip counting by 10s: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

Math Notes #5

There is a number word for each numeral. Numbers can be written in words and in symbols.