Math Intervention 3–5 Grade

94 Addition and Subtraction Concepts

Race to the Bottom

A game designed to build the concept

of partial differences

Materials:

Q (^) Two sets of 0–9 Number Cards (see page 72)
Q^ One set of 5–9 Number Cards
Q^ One set of 1–4 Number Cards
Q (^) Race to the Bottom Game Board
Q^ Number Line and two pawns
Directions:

1. Players shuffl e each set of number cards and place the cards
   face down in a pile near each of the template boxes on the game
   board. Note: The 5–9 cards are used for the tens digit of the minuend.
   The 1–4 cards are used for the tens digit of the subtrahend.


2. Players decide the ladder each person will use and place a
   pawn at the top of this ladder.


3. The player on the left fl ips over the top card in the fi rst pile and
   places it in the fi rst box. He fl ips over the top card in the second
   pile and places it in the second box.


4. The player on the right does the same with the third and fourth
   piles of cards and boxes.


5. Players read the equation. The goal is not to name the
   difference. Rather, the goal is to name the partial differences,
   for example, 63 – 27 = 40 – 4. Use the number line as needed.


6. The fi rst player to name the correct partial differences moves
   his pawn one step down the ladder. Used cards are placed
   under each pile of cards. Play continues until the winning
   player reaches the bottom of his ladder.

Content Differentiation:

Moving Back: Use base ten blocks or other manipulatives to show

the partial differences.

Moving Ahead: Try this game with 3-digit numbers.

PLAYERS:

2