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Grade 1 Math · Level 2, Add & Subtract to 20

Subtraction as a Missing Addend

How the lesson starts: Subtraction as a Missing Addend

1. Bella's carrot basket

   Hi friend! Bella the bunny picks carrots. Her basket holds 10. She has 8 so far. How many more does she need? Let's think like Bella!

2. Count up to 10

   Bella has 8 carrots. Count up to 10. 9, 10! She needs 2 more. 8 + 2 = 10. So 10 − 8 = 2. Same missing number!

3. Think addition

   6 + □ = 13, so 13 − 6 = □. From 6, add 4 to get 10. Add 3 more to get 13. 4 + 3 = 7. Both boxes are 7! Watch out! The box is not 13.