Tuesday, October 17, 2017

Strategies for Learning Addition Combinations

An excellent way you can help your student become a successful mathematician is by practicing math facts. Third graders should know their addition and subtraction facts 0-20 fluently, so that the transition to higher-level math is easier. Students can learn math facts in a variety of ways: using flash cards, filling in blank addition/subtraction charts, or using an online facts practice program. You can buy fact cards at the Dollar Store, Launching Success, or you can make your own using notecards. About 5 minutes of facts practice each night is adequate for most students this age.

If your child is fluent in addition and subtraction facts, feel free to start working on multiplication and division facts at home!

Strategies for Learning Addition Combinations

Add Zero Facts--like 6 + 0 and 0 + 4. Students learn the rule that when you add zero to any number, the number remains the same.

Count On Facts—3 + 4, 4 + 5, 5 + 6, 6 + 7, 7 + 8, 8 + 9, and 9 + 10. These are one or two more than the doubles. Students can use the doubles they know to learn these. “I know 5 + 5 is 10, so 5 + 6 is 1 more which is 11.”

Doubles—like 3 + 3 and 10 + 10. Students learn most of the doubles readily and can use the doubles they know to help with the harder doubles. “I know that 6 + 6 is 12, so 7 + 7 is 2 more, that’s 14.”

Doubles Plus or Minus One--like 4 + 3 and 5 + 6. Once students know their Doubles, this strategy is a breeze--it's just doubles and one more or one less.

Make Ten Facts—1 + 9, 2 + 8, 3 + 7, 4 + 6, 5 + 5, 6 + 4, 7 + 3, 8 + 2, and 9 + 1. Students need many experiences building all the ways there are to make 10 with manipulatives (tools they can hold) until they recognize these combinations.

Add Ten Facts--10 + 6 and 10 + 10. Because these combinations follow a structural pattern, students learn them readily once they have built them repeatedly with cubes or counted them out on the 100 chart.

Add Nine Facts – like 9 + 5 and 9 + 10. Students can think of these combinations this way: To solve 9 + 5, take one from the 5 and add it to the 9 to make 10. The 4 that are left are added to the 10; 10 + 4 = 14. Or, if we used 10 + 5 the answer would be 15, but because we added 1 extra when we take it away we get the answer 14.

Addition Fact Cards idea: Students work on addition combinations they are trying to learn better. They write a clue or strategy for each one. If the student does not have the combinations for 10 at recall there are games that can be requested that will help this
practice.

Examples:
4 + 3 =
3 + 4 =
Clue: I know 3 + 3 = 6, so 4 + 3 is one more which is 7.

5 + 3 =
3 + 5 =
Clue: I know 5 + 5 = 10. Three is 2 less than 5 so 10 – 2 = 8

6 + 3 =
3 + 6 =
Clue: I know 6 + 4 = 10. Three is one less than 4 so, 6 + 3 =9

8 + 3 =
3 + 8 =
Clue: I know that 8 needs 2 more to make 10 so I make the 3 into a 1, 10 + 1 = 11

7 + 3 =
3 + 7 =
Clue: I know my 10 combinations

9 + 3 =
3 + 9 =
Clue: I take one from the 3 and make 9 into a 10. 10 + 2 = 12

No comments:

Post a Comment