Let’s find the value of $309+501$309+501, by partitioning the numbers.
Fill in the box with the missing number.
$309=300+\editable{}$309=300+
Fill in the box with the missing number.
$501=\editable{}+1$501=+1
Find the value of $309+501$309+501.
selects and applies appropriate strategies for addition and subtraction with counting numbers of any size