Decompose Numbers to 10

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Answer Key & Explanations

Decompose Numbers to 10 · Kindergarten · Worksheet 2

1. 6 = ? + 6 Answer: 0 Solution: Since 0 + 6 = 6, we know that 6 = 0 + 6.
2. 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

3. 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.

4. Noah has 9 colorful marbles. He gives 4 marbles to his friend Sam. How many marbles does Noah have left? Answer: 5 Solution: Noah starts with 9 marbles. He gives away 4 marbles to Sam. To find how many are left, subtract: 9 - 4 = 5.
   Full step-by-step solution

   Step 1: Noah starts with 9 marbles. Step 2: He gives away 4 marbles to Sam. Step 3: To find how many are left, subtract: 9 - 4 = 5. Noah has 5 marbles left.

5. Liam has 8 toy cars. He puts 3 of them in a red box and the rest in a blue box. How many toy cars are in the blue box? Answer: 5 Solution: Liam starts with 8 toy cars in total. He puts 3 of these toy cars into a red box. This means we subtract 3 from the total number of cars to find out how many are left.
   Full step-by-step solution

   Step 1: Liam starts with 8 toy cars in total. Step 2: He puts 3 of these toy cars into a red box. This means we subtract 3 from the total number of cars to find out how many are left. Calculation: 8 - 3 = 5 Step 3: The problem says the rest of the cars go into the blue box. Since 5 cars are left after putting 3 in the red box, all of these go into the blue box. Step 4: Therefore, the number of toy cars in the blue box is 5.

6. 10 = 8 + ? Answer: 2 Solution: We know that 10 = 8 + ? Start with 8 and count up to 10: 8 → 9 → 10 We counted 2 more numbers to reach 10 So 8 + 2 = 10 The answer is 2.
   Full step-by-step solution

   Step 1: We know that 10 = 8 + ? Step 2: Start with 8 and count up to 10: 8 → 9 → 10 Step 3: We counted 2 more numbers to reach 10 Step 4: So 8 + 2 = 10 The answer is 2.

7. 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

8. 4 = ? + 3 Answer: 1 Solution: Since 1 + 3 = 4, we know that 4 = 1 + 3.
9. There are 4 red apples and 3 green apples in a bowl. How many apples are there in total? Answer: 7 Solution: Identify the number of red apples. There are 4 red apples. Identify the number of green apples.
   Full step-by-step solution

   Step 1: Identify the number of red apples. There are 4 red apples. Step 2: Identify the number of green apples. There are 3 green apples. Step 3: Add the number of red apples and green apples to find the total. Total apples = red apples + green apples Total apples = 4 + 3 Step 4: Perform the addition. 4 + 3 = 7 Step 5: State the final answer. There are 7 apples in total.

10. Tane sees 9 triangles on a page. 3 triangles are blue, and the rest are red. How many triangles are red? Answer: 6 Solution: Tane has 9 triangles in total. 3 triangles are blue. To find the red triangles, subtract the blue ones from the total: 9 - 3 = 6.
    Full step-by-step solution

    Step 1: Tane has 9 triangles in total. Step 2: 3 triangles are blue. Step 3: To find the red triangles, subtract the blue ones from the total: 9 - 3 = 6. There are 6 red triangles. The answer is 6.