Guided Strategy Development for Addition Facts
Guided Strategy Development for Addition Facts
One More Than and Two More Than
There are 36 facts that have at least one addend of 1 or 2.
- Story Problems involving 1 and 2 more.
- One More Than and Two More Than with Dice, Spinners, and Cards
Make a die labeled +1, +2, +1, +2, “one more”, and “two more.” Use with another die labeled 3, 4,5,6,7, and 8. After each roll of the dice, children should say the complete fact: “Four and two more is six.” Alternatively, roll one die and use a spinner with +1 on one half and +2 on the other half. Another option is to use cards and separate the 1 and 2 cards from the remaining cards.
Adding Zero
There are 19 facts that have zero as one of the addends.
- Story Problems involving Zero.
- What’s Alike? Zero Facts
Write about ten zero facts on the board, some with the zero first and some with the zero second. Discuss how all these facts are alike. Have children use counters and a part-part-whole mat to model the facts at their desk. (A part whole mat is a piece of paper folded in half so students can use counters to represent the addends (part) of the whole number.)
Using 5 as an Anchor
The use of an anchor is a reasoning strategy that builds on students’ knowledge of number relationships to help them derive facts from these relationships. For example, 7 is 5 + 2 and 6 is 5 + 1. A fact such as 6 + 7 can then be processed by a student by seeing the 5 in each number along with the “extras.” The student can add the 5 + 5 and then the extra 1 and 2 to equal 13. You can also use 5 frames and counters to build this number relationship.
Using 10 as an Anchor and 10 Facts
- Story Problem with Combinations that Make 10.
- Ten Frames
Place 2 ten frames on the overhead projector. Place counters on each-for example, 6 on one and 7 on the other. Flash on the overhead for about 5 seconds; then turn off. First ask students how many counters there were and then have students explain how they saw them.
- Say the 10 Fact
Hold up a ten-frame card, and have children say the “10 fact”. For a card with seven dots, the response is “seven and three is ten.” Later, with a blank ten-frame drawn on the board, say a number less than 10. Children start with that number and complete the “10 fact”. If you say, “four,” they say. “Four plus six is ten.”
Up Over 10
- Move to Make 10
Place 2 ten frames on the overhead projector. Place counters on each-for example, 6 on one and 8 on the other. Flash on the overhead for about 5 seconds; then turn off. First ask students how many counters there were and then have students explain how they moved them visually to make a ten as a strategy to find the sum.
- Make 10 on the Ten-Frame
Give students a mat with two ten-frames. Flash cards are placed next to the ten-frames, or a fact can be given orally. The students model each number in the two ten-frames and then decide on the easiest way to find the total without counting. Get the students to explain what they did. Focus especially on the idea that counters can be taken from one of the frames and moved to the other frame to make 10. Then you have 10 and whatever is left.
- Frames and Facts
Use ten frame cards with numbers representing 1-9. Match up two frames and have students solve. Start out with two addends, such as 8 + 4, and then move on to more difficult facts such as 7 + 6. Have the students explain orally how they found the sum.
- Double Images
Have students draw pictures to represent the fact for each of the doubles and include the basic fact on the card.
- Calculator Doubles
Use the calculator and enter the “double maker” (2 X). Have a student give you an example of a double. If they say 7 + 7, then have them press the 7 and = to see the sum of 14. After a few more examples have students practice their doubles on the calculator.
Near Doubles
- On the Double
Have students sort flash cards in to two categories. One pile for double addend (example: 3 + 3) and one for all the other facts. Ask the students to find the fact that will help them solve the double fact. One strategy students may choose is to use the near-double fact to help them solve.
Reinforcing Reasoning Strategies
The big idea behind the developing of reasoning strategies is helping students move away from counting and become more efficient until they are able to recall facts quickly and correctly.
Ask your students these types of questions to help them apply the reasoning strategies they have learned.
- If You Didn’t Know
Pose the following task to your class: If you did not know the answer to 8 + 5(or any fact that you want students to think about), what are some ways to get the answer? Explain how you didn’t just count in your head, but used a strategy to figure it out. Have student’s think-pair-share to discuss their ideas with a partner before sharing with the class.