Subject area: Mathematics
Grade level: 3rd Grade
MN math standards: 18.104.22.168-Add and subtract multi-digit numbers, using efficient and generalizable procedures based on knowledge of place value, including standard algorithms.
Objectives: For students to add and subtract multi-digit numbers using efficient procedures.
Time to be used: 40 minutes
List of materials:
· Smartboard Online game (http://www.learn4good.com/games/kids/double_digits.htm)
Before the lesson:
· Align the smartboard and have the game open with the screen on mute (http://www.learn4good.com/games/kids/double_digits.htm)
· Review with students about adding and subtracting multi-digit numbers; ask them if place value is important when answering these questions.
· Ask students “When in real life would we need to add or subtract 2 digit numbers?” Examples could be for cooking or measuring, building, etc.
· Have students get out their math notebooks and open to a blank sheet with their name on it and wait for further instruction.
During the lesson:
· Have students write an addition story using 2 digit numbers in their math notebooks.
· When they have finished, have students pass their math notebooks to their right to another next student. They should then write out the addition problem on the paper but only the steps based on place value.
· After the students have written out the steps, have them pass their notebooks again to the right to another student.
· This final round, the students should now work out the steps to get the answer. Once completed they should return the notebook back to the original owner.
· The original notebook owner now has the duty to double check if his group members answered it correctly. The student should answer the problem underneath it with his/her own work.
· Tell the students to turn to a new sheet of paper in their notebooks and bring it up on the floor in front of the smartboard.
· Turn on the screen and open up the online game.
· Split the classroom in two equal teams and pick one spokesperson from each. When a subtraction question is shown up on the smartboard, all members of the team must work out the problem in their notebooks and agree on the answer. When everyone has agreed, the spokesperson can then come up to the board and tap the answer they think is right (ABCD). Whichever team taps the right answer first, they get a point.
· Continue this game with all the questions and if you have extra time, start the addition game.
· Once the game is over, tally up all the team’s points and tell them whos the winner.
· Have the students return to their seats and put their notebooks away in their desks.
After the lesson:
· Ask students what they learned today.
· Ask them why it’s important to practice their subtraction.
· Ask why place value matters when subtracting and adding 2 digit numbers.
Assessment: Put “56-78=” up on the doc camera and have them answer it on a sheet of paper then turn it in.
Closure: Today we learned how to add and subtract 2 digit numbers but tomorrow we are going to solve real world problems involving whole numbers.
Appendix: Smartboard Online game (http://www.learn4good.com/games/kids/double_digits.htm)