Practice with the help of Spectrum Math Grade 1 Answer Key Chapter 2 Lesson 2.9 Counting Forward and Backward to 120 regularly and improve your accuracy in solving questions.
Spectrum Math Grade 1 Chapter 2 Lesson 2.9 Counting Forward and Backward to 120 Answers Key
Count forward. Write the missing numbers.
1. 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46
Answer:
36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46.
Explanation:
Missing letter pattern:
1 difference between the numbers.
=> 36,37,37 + 1 = 38 ,39, 40 + 1 = 41,42, 42 + 1 = 43, 44, 45, 45 + 1 = 46.
2. 92, 93, ____, 95, 96, ____, 98, 99, ____, ____, 102, 103
Answer:
92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103.
Explanation:
Missing letter pattern:
1 difference between the numbers.
=> 92, 93, 93 + 1 = 94, 95, 96, 96 + 1 = 97, 98, 99, 99 + 1 = 100, 100 + 1 = 101, 102, 103.
3. ___, 67, 68, ____, 70, 71, ____, 73, 74, 75, ___, 77
Answer:
66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77.
Explanation:
Missing letter pattern:
1 difference between the numbers.
=> 67 – 1 = 66, 67, 68, 68 + 1 = 69, 70, 71, 71 + 1 = 72, 73, 74, 75, 75 + 1 = 76, 77.
4. 100, 101, ___, 103, 104, ____, 106, ___, 108, 109, ____, 111
Answer:
100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111.
Explanation:
Missing letter pattern:
1 difference between the numbers.
=> 100, 101, 101 + 1 = 102, 103, 104, 104 + 1 = 105, 106, 106 + 1 = 107, 108, 109, 109 + 1 = 110, 111.
5. ___, 10, 15, ___, 25, 30, 35, ___, 45, 50, 55, ____
Answer:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60.
Explanation:
Missing letter pattern:
5 difference between the numbers.
=> 10 – 5 = 5, 10, 15, 15 + 5 = 20, 25, 30, 35, 35 + 5 = 40, 45, 50, 55, 55 + 5 = 60.
6. ___, 20, 30, ____, 50, ____, 70, 80, ___, ___, ___, ____
Answer:
10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120.
Explanation:
Missing letter pattern:
10 difference between the numbers.
=> 20 – 10 = 10, 20, 30, 30 + 10 = 40, 50, 50 + 10 = 60, 70, 80, 80 + 10 = 90, 90 + 10 = 100, 100 + 10 = 110, 110 + 10 = 120.
Count backward. Write the missing numbers.
7. 79, ___, 77, 76, ___, 74, 73, 72, ____, 70, 69, ____
Answer:
79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68.
Explanation:
Missing letter pattern:
1 difference between the numbers.
=> 79, 79 – 1 = 78, 77, 76, 76 – 1 = 75, 74, 73, 72, 72 – 1 = 71, 70, 69, 69 – 1 = 68.
8. 84, ____, 82, 81, ___, 79, 78, 77, ____, ____, 74, 73
Answer:
84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73.
Explanation:
Missing letter pattern:
1 difference between the numbers.
=> 84, 84 – 1 = 83, 82, 81, 81 – 1 = 80, 79, 78, 77, 77 – 1 = 76, 76 – 1 = 75, 74, 73.
9. 24, 22, ____, 18, 16, ___, 12, ____, 8, 6, ___, 2
Answer:
24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2.
Explanation:
Missing letter pattern:
2 difference between the numbers.
24, 22, 22 – 2 = 20, 18, 16, 16 – 2 = 14, 12, 12 – 2 = 10 , 8, 6, 6 – 2 = 4, 2.
10. 120, ____, 110, 105, ____, 95, 90, ___, ____, 75, 70, 65
Answer:
120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65.
Explanation:
Missing letter pattern:
5 difference between the numbers.
=> 120, 120 – 5 = 115, 110, 105, 105 – 5 = 100, 95, 90, 90 – 5 = 85, 85 – 5 = 80, 75, 70, 65.
11. 75, 70, ____, 60, 55, ___, 45, 40, 35, ___, 25, ____
Answer:
75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20.
Explanation:
Missing letter pattern:
5 difference between the numbers.
=> 75, 70, 70 – 5 = 65, 60, 55, 55 – 5 = 50, 45, 40, 35, 35 – 5 = 30, 25, 25 – 5 = 20.
12. ___, ____, 90, ___, 70, 60, ____, ____, 30, ____
Answer:
110, 100, 90, 80, 70, 60, 50, 40, 30, 20.
Explanation:
Missing letter pattern:
10 difference between the numbers.
=> 100 + 10 = 110, 90 + 10 = 100, 90, 90 – 10 = 80, 70, 60, 60 – 10 = 50, 50 – 10 = 40, 30, 30 – 10 = 20.