Missing Addend

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Missing Addend · Grade 1 · Worksheet 2

1. Ethan baked 10 cookies. Ethan baked some more cookies. Now there are 13 cookies in total. How many more cookies did Ethan bake? Answer: 3 Solution: Ethan baked 10 cookies first. Now there are 13 cookies in total. The extra cookies baked are the difference: 13 - 10 = 3.
   Full step-by-step solution

   Step 1: Ethan baked 10 cookies first. Step 2: Now there are 13 cookies in total. Step 3: The extra cookies baked are the difference: 13 - 10 = 3. Ethan baked 3 more cookies.

2. Emma has 7 stickers. She wants to have 12 stickers in her collection. How many more stickers does Emma need to get? Answer: 5 Solution: Emma starts with 7 stickers. She wants to have 12 stickers total. To find how many more she needs, subtract what she has from what she wants: 12 - 7 12 - 7 = 5 Emma needs 5 more stickers.
   Full step-by-step solution

   Step 1: Emma starts with 7 stickers. Step 2: She wants to have 12 stickers total. Step 3: To find how many more she needs, subtract what she has from what she wants: 12 - 7 Step 4: 12 - 7 = 5 Emma needs 5 more stickers.

3. 15 - ? = 8 Answer: 7 Solution: We know that 15 minus some number equals 8 Think about what number plus 8 equals 15 8 + 7 = 15 So 15 - 7 = 8 The answer is 7.
   Full step-by-step solution

   Step 1: We know that 15 minus some number equals 8 Step 2: Think about what number plus 8 equals 15 Step 3: 8 + 7 = 15 Step 4: So 15 - 7 = 8 The answer is 7.

4. Noah sees 8 ladybugs on a leaf. Some more ladybugs join them on the leaf. Now there are 15 ladybugs in all. How many ladybugs joined? Answer: 7 Solution: Start with the 8 ladybugs that are already on the leaf. Step 2: The total number of ladybugs is 15. Step 3: To find how many joined, think 8 + ?
   Full step-by-step solution

   Step 1: Start with the 8 ladybugs that are already on the leaf. Step 2: The total number of ladybugs is 15. Step 3: To find how many joined, think 8 + ? = 15. Step 4: Count up from 8 to 15: 9, 10, 11, 12, 13, 14, 15. That is 7 more. Step 5: So 8 + 7 = 15. The answer is 7.

5. ? + 9 = 17 Answer: 8 Solution: The equation is ? + 9 = 17. To find the missing number, think about what number, when added to 9, equals 17.
   Full step-by-step solution

   Step 1: The equation is ? + 9 = 17. Step 2: To find the missing number, think about what number, when added to 9, equals 17. Step 3: You can count up from 9 until you reach 17: 10, 11, 12, 13, 14, 15, 16, 17. That is 8 more numbers. Step 4: Therefore, the missing number is 8. The answer is 8.

6. There are 8 crayons in a box. 5 crayons are red and the rest are blue. How many blue crayons are there? Answer: 3 Solution: We know there are 8 crayons in total. 5 of them are red. The rest are blue.
   Full step-by-step solution

   Step 1: Understand the problem. We know there are 8 crayons in total. 5 of them are red. The rest are blue. Step 2: Determine the number of blue crayons. To find the number of blue crayons, subtract the number of red crayons from the total number of crayons. Step 3: Perform the calculation. Total crayons = 8 Red crayons = 5 Blue crayons = Total crayons - Red crayons Blue crayons = 8 - 5 Step 4: Write the result. 8 - 5 = 3 Step 5: State the answer. There are 3 blue crayons.

7. Lily has 8 flowers in her garden. After planting some more flowers, she now has 17 flowers in total. How many flowers did Lily plant? Answer: 9 Solution: Lily started with 8 flowers After planting more flowers, she has 17 total To find how many she planted, subtract the starting amount from the total: 17 - 8 17 - 8 = 9 Lily planted 9 flowers.
   Full step-by-step solution

   Step 1: Lily started with 8 flowers Step 2: After planting more flowers, she has 17 total Step 3: To find how many she planted, subtract the starting amount from the total: 17 - 8 Step 4: 17 - 8 = 9 Lily planted 9 flowers.

8. Aroha has 10 crayons. Aroha finds some more crayons. Now Aroha has 16 crayons. How many crayons did Aroha find? Answer: 6 Solution: Aroha started with 10 crayons. After finding more, Aroha has 16 crayons. The number found is the difference: 16 - 10 = 6.
   Full step-by-step solution

   Step 1: Aroha started with 10 crayons. Step 2: After finding more, Aroha has 16 crayons. Step 3: The number found is the difference: 16 - 10 = 6. Aroha found 6 crayons.

9. Lily has 8 seashells in her collection. Her brother gives her some more seashells from the beach. Now Lily has 17 seashells. How many seashells did her brother give her? Answer: 9 Solution: Lily started with 8 seashells. After her brother gave her some, she had 17 seashells.
   Full step-by-step solution

   Step 1: Lily started with 8 seashells. Step 2: After her brother gave her some, she had 17 seashells. Step 3: To find how many her brother gave her, subtract the starting amount from the total: 17 - 8 Step 4: 17 - 8 = 9 Her brother gave her 9 seashells.