Elementary School Lessons

Properties of Addition

• The commutative property of addition tells us that the order or position of the addends does not affect the sum.

• The associative property of addition tells that the grouping of the addends does not affect the sum.

• The identity property of addition tells us that when zero is added to a number or when a number is added to zero, the sum is the number itself.

July 22

Math Prep

Number Words 1 – 10

1. one
2. two
3. three
4. four
5. five
6. six
7. seven
8. eight
9. nine
10. ten

Math Prep

One More Order

One less Order

1. 1 more than 18 is _________
2. 1 more than 67 is _________
3. 1 less than 35 is __________
4. 1 less than 57 is __________

Addition Concepts

• Addition is the process of putting two or more numbers together. It is also the union of two or more sets of objects.

• The numbers that are added are called addends.

• The answer in addition is sum or total.

• The symbol for addition is + which is read as “plus”.

Math Prep

Greater Than – Less than – Equal

We use the > sign if the first number is greater than the second number.

We use the < sign if the first number is less than the second number.

We use the = sign if the numbers are the same or have the same value.

Roman Numerals

• Numerals V and L are never repeated.

• Numeral I and X may be repeated at most three times.

• When a symbol with a lesser value comes before a symbol with a greater value, subtract their values.

• When a symbol with a greater value comes before a symbol with a lesser value, add their values.

Math Prep

Comparing Numbers

Check the number that is LESS: 94 49

Check the number that is MORE: 80 70