Decompose Numbers to 10

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Answer Key & Explanations

Decompose Numbers to 10 · Kindergarten · Worksheet 3

1. 9 = ? + 9 Answer: 0 Solution: Since 0 + 9 = 9, we know that 9 = 0 + 9.
2. Emma has 6 colorful stickers. She gives 2 stickers to her friend Noah. How many stickers does Emma have left? Answer: 4 Solution: Emma starts with 6 stickers. She gives 2 stickers to Noah. To find how many she has left, subtract 2 from 6: 6 - 2 6 - 2 = 4 Emma has 4 stickers left.
   Full step-by-step solution

   Step 1: Emma starts with 6 stickers. Step 2: She gives 2 stickers to Noah. Step 3: To find how many she has left, subtract 2 from 6: 6 - 2 Step 4: 6 - 2 = 4 Emma has 4 stickers left.

3. 10 = 6 + ? Answer: 4 Solution: 10 = 6 + ? The equation says that 10 is equal to 6 plus some unknown number. To find the unknown number, we need to isolate it on one side of the equation.
   Full step-by-step solution

   We start with the equation: 10 = 6 + ? Step 1: The equation says that 10 is equal to 6 plus some unknown number. Step 2: To find the unknown number, we need to isolate it on one side of the equation. Step 3: Subtract 6 from both sides of the equation to keep it balanced: 10 - 6 = 6 + ? - 6 Step 4: Simplify both sides: On the left: 10 - 6 = 4 On the right: 6 - 6 + ? = 0 + ? = ? Step 5: So we have: 4 = ? Step 6: Therefore, the unknown number is 4. Final answer: 4

4. 9 = ? + 7 Answer: 2 Solution: Since 2 + 7 = 9, we know that 9 = 2 + 7.
5. 10 = ? + 5 Answer: 5 Solution: Since 5 + 5 = 10, we know that 10 = 5 + 5.
6. Liam has 8 toy cars. He puts 3 cars in the red box and the rest in the blue box. How many cars does Liam put in the blue box? Answer: 5 Solution: Liam starts with 8 toy cars. He puts 3 cars in the red box. This means we subtract 3 cars from the total number of cars.
   Full step-by-step solution

   Liam starts with 8 toy cars. Step 1: He puts 3 cars in the red box. This means we subtract 3 cars from the total number of cars. Calculation: 8 - 3 = 5 Step 2: The problem says "the rest" go in the blue box. After putting 3 in the red box, the number of cars left is the number that go in the blue box. Reasoning: The rest of the cars means the cars that are not in the red box. Therefore, Liam puts 5 cars in the blue box.

7. Ava has 2 crayons. 0 are red and the rest are blue. How many blue crayons does Ava have? Answer: 2 Solution: Ava has 2 crayons total. 0 are red, so we find the blue ones by subtracting: 2 - 0 = 2.
   Full step-by-step solution

   Step 1: Ava has 2 crayons total. Step 2: 0 are red, so we find the blue ones by subtracting: 2 - 0 = 2. The answer is 2.

8. Sarah has 2 crayons. 1 are red and the rest are blue. How many blue crayons does Sarah have? Answer: 1 Solution: Sarah has 2 crayons total. 1 are red, so we find the blue ones by subtracting: 2 - 1 = 1.
   Full step-by-step solution

   Step 1: Sarah has 2 crayons total. Step 2: 1 are red, so we find the blue ones by subtracting: 2 - 1 = 1. The answer is 1.

9. 10 = ? + 7 Answer: 3 Solution: Since 3 + 7 = 10, we know that 10 = 3 + 7.
10. 7 = 4 + ? Answer: 3 Solution: 7 = 4 + ? We want to find the number that, when added to 4, gives 7. 4 + ?
    Full step-by-step solution

    We start with the equation: 7 = 4 + ? Step 1: We want to find the number that, when added to 4, gives 7. So we can rewrite the equation as: 4 + ? = 7 Step 2: To find the unknown number, we subtract 4 from both sides of the equation: ? = 7 - 4 Step 3: Now we calculate 7 minus 4: 7 - 4 = 3 Step 4: So the missing number is 3. We check: 4 + 3 = 7, which matches the original equation. Final answer: 3