Target 100: Addition

Summary

Students use base 10 blocks to represent adding 1-digit and 2-digit numbers in a race to reach 100.

Curriculum content

• Addition of 1-digit and 2-digit numbers
• Place value up to 100

Materials

Card sets

• 1 set of Mathletics number cards 1 to 20 1-20

Concrete

• Base 10 blocks (ones, tens, hundreds)

Printables

• Place value mat Download place value mat

How to play

Set up

1. Arrange students into pairs or small groups.
2. Shuffle or mix up number cards and place them in a pile face down.
3. Give each student a place value mat and base 10 blocks.

Rules

1. Player 1 chooses the top card and makes that number on their place value mat using the base 10 blocks.
2. The card is returned to the bottom of the pile.
3. Each player in turn takes a number card and makes the number on their mat.
4. On their second and subsequent turns, players take another card from the pile, collect base 10 blocks to represent the value and add it to their place value mat.
5. If a player reaches 10 or more in the ones place, they need to trade 10 ones for a ten.
6. Continue taking turns, selecting a card and adding to the place value mat.
7. The winner is the first player to reach or exceed 100.

Variations

CHANGE it down

• Use cards 1 to 10.
• Reduce the target to 50.
• Work in collaborative pairs to assist in verbalizing thinking.

CHANGE it up

• Students record calculations throughout the game.
• Use numeral cards 0 to 9 but have students select 2 cards and use them to create a 2-digit number so they are always adding a 2-digit number.
• Make the winner the player that reaches 100 exactly and players can choose to add or subtract their total.
• Extend the target total to 200.

What to look for

• Are students able to represent numbers accurately using base 10 blocks?
• Do students swap 10 ones for a ten at the appropriate time?
• Are students able to use mathematical language to explain their representations?