Unit 1 - Place Value, Addition, Subtraction, Estimation
Standard Form - Writing numbers using a digit for the value of each number.
Expanded Form - Writing numbers by writing the value of each number and connecting them with addition signs.
Word Form - When you represent a number with words.
Here is a reference sheet on all three number forms.
Addition - Remember to align the place values vertically before you begin adding.
Subtraction - Remember...subtraction is not commutative...you cannot flip flop the numbers and get the same result. Please regroup from the number directly to the left if possible.
Estimation - This should always be done before determining the sums or differences. Why would you estimate if you already know the total? To estimate, round both numbers to the highest place value they both share, then add or subtract. Examples of this are in the reference sheet below.
