In this topic, students will:
use models to add 2-digit numbers and then explain the work
add 2-digit numbers using models
add using place value and partial sums
add using mental math, place value, and partial sums
add using place-value strategies and mental math
add three or four 2-digit numbers
practice using strategies to add more than two numbers
Vocabulary:
Regroup - the process of making groups of tens when carrying out operations like addition and subtraction with two-digit numbers
Partial sums - when you add numbers the sum of one of the place values.
Mental math - math you do in your head
At-home Practice:
Supplies:
deck of cards (remove face cards)
paper and pencil
Each player turns over two cards to make a two-digit number. Each player adds the numbers together (paper may be used). (ex. Player 1 draws a 3 and 5 to make 35. Player 2 draws a 2 and 7 to make 27. Players will add 35 and 27 together.) Compare answers. If each player is correct they win their cards. If one player is incorrect the other player wins all of the cards. If both players are incorrect no one wins the cards. Continue playing until the cards are gone. The person with the most cards wins the game.