Building addition and subtraction through counting and grouping
These tasks require students to determine how many would be in a collection resulting from adding or subtracting.
To find the answer to 7 + 6, a student might start with 7 and count on, saying, "Seven…8,9,10,11,12,13". Alternatively, a student could say that six and six make twelve (by using knowledge of doubles) and one more is thirteen. The use of doubles is quite common as a transition from relying on counting by ones. Some students will be able to "bridge to ten". This requires anticipating how many are needed to make ten and then splitting six into three and three.