Navigate

Summary

Students add and subtract 10s and 1s to navigate across the 100 chart to reach the chosen end point.

Curriculum content

• Compare, order, read and represent numbers to 100
• Apply place value understanding of 10s and 1s

Addition and subtraction

• Record number sentences using drawings, words, numerals and the symbols +, – and =
• Apply strategies and skills for addition and subtraction

Materials

Card sets

• 1 set of Mathletics number cards 0 to 9 0-9

Concrete

• 2 coloured counters
• 1 erasable marker

Printables

• 100 chart (laminated) Download 100 chart - CAL Download 100 chart - Tabloid-CA
• Navigate game sheet per pair

How to play

Set up

1. Arrange students into pairs or small groups of 3 to 4 (groups will require an A3 100 chart)
2. Give each pair a 100 chart and 2 sets of Mathletics number cards 0 to 9.
3. Assign coloured counter per player (different colours).
4. Shuffle or mix up the cards and place them in a pile face down.

Rules

1. Player 1 selects 2 cards and uses them to make a 2-digit starting number. Place both or all playing counters on the starting number.
2. Player 2 selects 2 cards and uses them to make a 2-digit target number. Mark the target number with an erasable marker.
3. Cards are returned to the pile. Shuffle or mix up again.
4. In turn, each player turns over a number card. The player chooses whether to move up or down by adding or subtracting that number of 10s or 1s.
5. Each player records their new position using their coloured counter.
6. The winner is the first player to reach the target number.

Variations

CHANGE it down

• Alter the starting point. Ask students to create a low number to encourage addition and a high number to encourage subtraction.

CHANGE it up

• Ask students to select a starting number and an end number anywhere on the 100 chart. Get pairs to share 1 set of 1 to 9 Mathletics cards. Each player selects 2 cards. They can select only 1 of these cards to add or subtract.

What to look for

• Are students using 100 chart confidently to add 10s and 1s?
• Are students able to record addition and subtraction number sentences?
• Are students able to work ahead and alter their calculations to fit the number of moves they need to make?
• Ask students to explain their calculation strategies. Look for students using efficient mental strategies such as subtract 20, add 2 to subtract 18. Look for students who use inefficient strategies such as counting on to add and counting back to subtract.