Under the title Addition and Subtraction Safari: Facts to 20, five parts each rehearse one named strategy. Students count on from 9, 12, 15 and 18, break numbers apart to make a ten, use 7 + 5 = 12 to solve 12 - 5, turn doubles into near doubles, and close with a Fact Speed Run of quick facts like 10 + 7 and 16 - 6. The answer key gives every result, part by part.
1.OA.5
“Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).”
Part 1 writes the counting sequence into the problem itself, so 15 - 2 appears as '15... 14, 13'.
1.OA.6
“Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8+ 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13- 3 - 1 = 10 − 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).”
The five parts map onto the strategies the standard lists: counting on, making ten, decomposing toward ten in 14 - 6, related facts and near doubles.
Four problems with the counting sequence partly written out, such as 9 + 3 shown as '9... 10, 11, 12'. Students finish 12 + 4, 15 - 2 and 18 - 3 the same way.
Fill-in frames decompose each fact step by step: 8 + 6 = 8 + 2 + ______ = 10 + ______ = ______, then 9 + 7, and the subtraction version 14 - 6.
Each item gives an addition fact and asks for the linked subtraction, starting with: if 7 + 5 = 12, then 12 - 5 = ______.
Four paired lines such as 6 + 6 = ______ so 6 + 7 = ______, running through 7 + 7, 8 + 8 and 5 + 5.
A grid of facts to finish as fast as possible, opening with 10 + 7 and 16 - 6.
One part per day
The five parts split naturally into a week of warm-ups, each one rehearsing a single strategy before the Friday speed run.
Spot the default strategy
Watch Part 5 closely. A student who solves 16 - 6 instantly but stalls on 8 + 6 has memorized facts without the make-a-ten structure from Part 2.
Intervention group
The scaffolded frames in Part 2 give you the exact wording for a small-group think-aloud: 8 plus 2 gets to 10, then 4 more.
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