Subtraction race to 20

Summary

Students practise subtraction facts within 10 in a race to reach 20.

Curriculum content

• Subtract numbers within 10

Materials

Card sets

• 1 set of Mathletics number cards 0 to 10 0-10

Concrete

• 2 different coloured counters

Printables

• Number line from 0 to 20 Download number line 0-20 - CAL Download number line 0-20 - Tabloid-CA

How to play

Set up

1. Arrange students into pairs. 
2. Shuffle or mix up cards and place them in a pile face down.
3. Each student places their counter on 0 on the number line.

Rules

1. Player 1 turns over 2 cards and subtracts the smaller number from the larger number.
2. Player 1 moves their counter that number of spaces along the number line.
3. Used cards are returned to the bottom of the pile.
4. Player 2 turns over 2 cards and subtracts the smaller number from the larger number.
5. Player 2 moves their counter that number of spaces along the number line.
6. Players continue taking turns.
7. If a player would go beyond 20 if their number was added, they need to subtract instead.
8. The winner is the first player to land exactly on 20.

Variations

CHANGE it down

• Provide concrete objects or an additional number line for support with the subtraction.
• Use Mathletics number cards 0 to 5 and race to 20 using the addition of 2 cards rather than subtraction.

CHANGE it up

• Race to 50 using Mathletics number cards 0 to 20.

What to look for

• Are students able to fluently subtract 2 numbers within 10?
• What strategies are students using to subtract 2 numbers (eg, counting back using their fingers)?
• Do students rely on concrete materials?