In this topic, students will:
use counting on to add numbers and add numbers in any order
use doubles and near doubles to add quickly and accurately
use the strategy of making a ten to add quickly and accurately
use number patterns on an addition facts table to complete addition equations
count on and count back on a number line
think addition to subtract quickly and accurately
make a 10 to subtract quickly and accurately
Add and subtract quickly and accurately using mental math strategies
use addition and subtraction to solve word problems
Vocabulary:
Equation - an equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.
Addends - numbers that are added.
Sum - the answer in an addition equation.
Doubles - addition facts that have two addends that are the same (5 + 5 = 10).
Near doubles - addition facts that are close (5 + 4 = 9).
Difference - the answer in a subtraction equation.
Bar diagram - a model for addition and subtraction that shows the parts and the whole.
At-home Practice:
Supplies:
deck of cards (Remove all face cards)
Turn over one card. The first player to “double” that number and add 1 wins the card. (ex. a 3 is turned over, the players would add 3 + 3 , add 1, and call out 7). Play continues until all cards are used. The player with the most cards at the end is the winner.
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Supplies:
deck of cards (Remove all face cards)
Turn over one card. The first player to “double” that number wins the card. (ex. a 4 is turned over, the players would add 4+4 and call out 8). Play continues until all cards are used. The player with the most cards at the end is the winner.
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Supplies:
deck of cards - (Remove all face cards)
Divide the deck evenly among the players. Player 1 turns over a card. Then Player 2 turns over a card and counts on that many. If he/she is correct, Player 2 keeps both cards. If not, Player 1 keeps the cards. Next, Player 2 turns over a card first, then Player 1 turns over a card and counts on. Play continues until all cards are used. The player with the most cards at the end is the winner!