standard_description: 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).
problem_activity: Stage 1: Nearest Ten or Hundred
Required Preparation
Materials to Gather
Colored pencils, crayons, or markers
Number cards 0–10
Paper clips
Materials to Copy
Blackline Masters
Tic Tac Round Stage 1 Gameboard
Tic Tac Round Stage 1 Spinner

Narrative
Students remove the cards that show 10 before they start. Then they choose three number cards and make a three-digit number. They spin the spinner to get a place value to round to. Students write their number in any space on the board, each partner using a different color. The first player to get three in a row wins.


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