Some games and activities involving number cards, flash cards and playing cards.
After students learn the meaning of addition and subtraction (using concrete materials), they're ready to master the facts. Students can say that they've achieved mastery when they're able to find the answer without counting on their fingers.
A rectangle divided into parts and whole can help students learn addition facts. Let's say they're asked to solve 8 + 4 = ? Using number cards and counters, they end up with something that looks like this:
Students count only the smaller addend of the fact. In this case, they start by saying "eight" and then counting by ones from 9 to 12.
Next, the students learn all the addition facts to sums of 10, starting with the facts that have 0, 1 and 2 as the addends. Except for 3 + 3, the students now have all the facts for the sums of 1, 2, 3, 4, 5 and 6.
The sum of 7 has two facts that need to be learned: 4 + 3 and 3 + 4. The sum of 8 has the facts 4 + 4, 5 + 3 and 3 + 5. The sum of 9 has 4 + 5, 5 + 4,6 + 3 and 3 + 6.The sum of 10 has 5 + 5. Thus, there are only 11 facts to learn that have addends greater than 2.
The subtraction facts that have sums up to 10 should be learned only after the addition facts are mastered.
Why learn all of the facts for a given sum? Simply because it's more productive than learning isolated facts.
Triangular flash cards, can be used to show the relationship of addition and subtraction in the family of numbers up to the sum of 10.
In response to a flash card like the one shown below, the students write: 4+3=7,3+4=7,7-4=3and7 -3 =4.
One way to assess students' understanding of addition and subtraction is to challenge them with a "reverse activity." In this activity, you give the student one fact and from the information given, he or she must write the the other three related facts. Example: 8 - 3 = 5. The students write: 3 + 5 = 8; 5 + 3 = 8; 8 5=3.
Solitaire. Learning all the facts for the sums of 11 to 18 is a bit more difficult, but you can lighten the load considerably by making a game of it. For example, have your students try games of Solitaire to learn the facts for the sums of 11 to 14. All they need is a deck of cards.
To learn the facts up to the sum of 11, have them remove all of the jacks, queens, kings and jokers from the deck. They then shuffle the cards and place them on a table, face up, in three rows with three cards in each row.
The object of the game is to make sums of 11 by picking up and discarding two cards at a time. For example, the player might pick up a 10 and an ace (which counts as 1), then a 7 and a 4, a 2 and a 9, and an 8 and a 3, If there are no facts for the sum of 11 in the nine cards, another row of three is laid out on the top or the bottom. The player has all the facts when no cards are left on the table or in the hand.
Games for the sums of 12,13 and 14 are played the same way, with the following exceptions. For the sum of 12, the four jacks are placed in the deck; each jack counts as 11. For the sum of 13, the four queens, each counting as 12, are added to the deck, and for the sum of 14, the four kings, each counting as 13, are added. Students keep playing each game until they know all the facts for the given sums.
Concentration. This game is played by two players and 16 cards with numbers that can be used to make 15. The cards are three 9's, three 6's, three 8's, three Ts, two 10's and two 5's.
One player lays out four rows of four cards face down. The other player turns over two cards. If they add up to 15, they are removed and the player gets another turn. If they do not add to 15, they are turned face down and the first player gets a turn.
The player with the most cards at the end is the winner. There are many variations of this game.
Lola May is a mathematics consultant, a former Math Consultant for the Winnetka (IL) Public Schools and a Teaching Editor of Teaching K-8.
Addition facts for sums with 5 and 6
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You can divide five elephants into groups of two and three: Also, you can divide five elephants into groups of zero and five: | |
What kind of groupings can you make? Think of ALL the possibilities, and write them down here:
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5 = ___ + ___ 5 = ___ + ___ |
5 = ___ + ___ 5 = ___ + ___ |
5 = ___ + ___ 5 = ___ + ___ | ||
Drill
What number is missing? Don't write the answer down but just think it in your head. Go over and over again these problems with your teacher or in your head until you know the missing numbers by heart.
1 + 2 + 0 + |
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4 + 3 + 5 + |
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What kind of two groups can you divide six hippos? Do the grouping and write the addition facts.
| 6 = 0 + 6 |
6 = 6 + 0 |
6 = 1 + 5 |
6 = ___ + ___ |
6 = ___ + ___ |
6 = ___ + ___ |
6 = ___ + ___ |
Drill. What number is missing? Don't write the answer down but just think it in your head. Go over and over again these problems with your teacher or in your head until you know the missing numbers by heart.
1 + 2 + 0 + 6 + |
4 + 3 + 5 + 0 + |
Example problem types
1. Complete the X's to make 6 or 5 and write the addition sentence.
XXX 3 + __ = 6 |
X 1 + __ = 5 |
XXXX __ + __ = 5 |
0 + __ = 6 |
2. What is similar about these problems?
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3. Find the missing addend - from memory, not by counting. Use the addition facts you've learned.
0 + __ = 6 4 + __ = 6 __ + 2 = 5 |
1 + __ = 5 2 + __ = 6 __ + 1 = 6 |
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