Use addition and subtraction to solve one-step word problems. Students will learn that some words refer to addition, others subtraction:

Addition | Subtraction |

in all | fewer |

total | less |

sum | difference |

altogether | how many more |

add | how many left |

both | subtract |

plus | minus |

take away |

For a lesson, watch this, this, this, and this. For practice, have students do this and this.

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Conclude by leading this investigation:

Streets and Sidewalks (addition, subtraction, pattern)

by MathPickle

2.OA.A.1: Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.