Give each student 20 counters and a double ten-frame.

Ask students to show 14 on the double ten-frame, filling the top ten-frame before placing any counters on the bottom ten-frame. Below are suggested questions for this activity:

• How many counters are in the top ten-frame?
• How many are in the bottom ten-frame?
• Fourteen is 10 and how many more?
• Show 15 on the ten-frame. Fifteen is 10 and how many more?
• Is 14 more or less than 15? How do you know?
• Use what you know about 4 and 5 to help you understand the relationship between 14 and 15? Explain.
• Show 13 on the ten-frame. Now show 11. What did you do to show 11?
• Show 14 on the ten-frame. Now show 9. Did you add or remove counters? How many?
• Now you have 9 counters on the ten-frame. What would you need to do to show 18 on the ten-frame?

Prepare numeral cards for 11-20. Show a numeral card to students to model on the double ten-frame. Ask, "__ is how many more than 10?" Choose other numeral cards and repeat. Show double 10-frame flash cards (with dots filled in, representing numbers 10-20) for about 3 seconds each. Ask students to tell the number represented on the double ten-frame and explain how they saw the number. A student might say she knew it was 18 because there were 2 empty boxes in the bottom row (indicating 8), and she knew that 8 and 10 is 18.)