Skip-count backward to the start
4.NBT.A.2
Generated variants — 12
Starting from and skip-counting up by 4 times, you reach . Find the number .
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1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 4 times lands on 2348. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 4 steps.
- After 4 steps the number is 2348.
Unknowns
- The starting number.
Constraints
- Counting up by 10 4 times means adding 10 a total of 4 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 2348.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 2308 + 10 = 2318, 2318 + 10 = 2328, 2328 + 10 = 2338, 2338 + 10 = 2348. 4 jumps of 10 from 2308 reach 2348, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 4 skip-count steps of 10 as a total of 40.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.
Starting from and skip-counting up by 5 times, you reach . Find the number .
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1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 5 times lands on 3415. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 5 steps.
- After 5 steps the number is 3415.
Unknowns
- The starting number.
Constraints
- Counting up by 10 5 times means adding 10 a total of 5 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 3415.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 3365 + 10 = 3375, 3375 + 10 = 3385, 3385 + 10 = 3395, 3395 + 10 = 3405, 3405 + 10 = 3415. 5 jumps of 10 from 3365 reach 3415, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 5 skip-count steps of 10 as a total of 50.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.
Starting from and skip-counting up by 5 times, you reach . Find the number .
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1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 5 times lands on 4267. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 5 steps.
- After 5 steps the number is 4267.
Unknowns
- The starting number.
Constraints
- Counting up by 10 5 times means adding 10 a total of 5 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 4267.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 4217 + 10 = 4227, 4227 + 10 = 4237, 4237 + 10 = 4247, 4247 + 10 = 4257, 4257 + 10 = 4267. 5 jumps of 10 from 4217 reach 4267, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 5 skip-count steps of 10 as a total of 50.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.
Starting from and skip-counting up by 4 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 100 4 times lands on 4870. Find the starting number.
Givens
- Each skip-count step adds 100.
- There are 4 steps.
- After 4 steps the number is 4870.
Unknowns
- The starting number.
Constraints
- Counting up by 100 4 times means adding 100 a total of 4 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 100 by counting back from 4870.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 4470 + 100 = 4570, 4570 + 100 = 4670, 4670 + 100 = 4770, 4770 + 100 = 4870. 4 jumps of 100 from 4470 reach 4870, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 4 skip-count steps of 100 as a total of 400.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 100s through four-digit numbers to reach the start.
Starting from and skip-counting up by 3 times, you reach . Find the number .
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1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 3 times lands on 5230. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 3 steps.
- After 3 steps the number is 5230.
Unknowns
- The starting number.
Constraints
- Counting up by 10 3 times means adding 10 a total of 3 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 5230.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 5200 + 10 = 5210, 5210 + 10 = 5220, 5220 + 10 = 5230. 3 jumps of 10 from 5200 reach 5230, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 3 skip-count steps of 10 as a total of 30.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.
Starting from and skip-counting up by 2 times, you reach . Find the number .
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1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 100 2 times lands on 5310. Find the starting number.
Givens
- Each skip-count step adds 100.
- There are 2 steps.
- After 2 steps the number is 5310.
Unknowns
- The starting number.
Constraints
- Counting up by 100 2 times means adding 100 a total of 2 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 100 by counting back from 5310.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 5110 + 100 = 5210, 5210 + 100 = 5310. 2 jumps of 100 from 5110 reach 5310, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 2 skip-count steps of 100 as a total of 200.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 100s through four-digit numbers to reach the start.
Starting from and skip-counting up by 5 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 100 5 times lands on 6500. Find the starting number.
Givens
- Each skip-count step adds 100.
- There are 5 steps.
- After 5 steps the number is 6500.
Unknowns
- The starting number.
Constraints
- Counting up by 100 5 times means adding 100 a total of 5 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 100 by counting back from 6500.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 6000 + 100 = 6100, 6100 + 100 = 6200, 6200 + 100 = 6300, 6300 + 100 = 6400, 6400 + 100 = 6500. 5 jumps of 100 from 6000 reach 6500, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 5 skip-count steps of 100 as a total of 500.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 100s through four-digit numbers to reach the start.
Starting from and skip-counting up by 4 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 4 times lands on 6792. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 4 steps.
- After 4 steps the number is 6792.
Unknowns
- The starting number.
Constraints
- Counting up by 10 4 times means adding 10 a total of 4 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 6792.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 6752 + 10 = 6762, 6762 + 10 = 6772, 6772 + 10 = 6782, 6782 + 10 = 6792. 4 jumps of 10 from 6752 reach 6792, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 4 skip-count steps of 10 as a total of 40.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.
Starting from and skip-counting up by 3 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 100 3 times lands on 7600. Find the starting number.
Givens
- Each skip-count step adds 100.
- There are 3 steps.
- After 3 steps the number is 7600.
Unknowns
- The starting number.
Constraints
- Counting up by 100 3 times means adding 100 a total of 3 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 100 by counting back from 7600.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 7300 + 100 = 7400, 7400 + 100 = 7500, 7500 + 100 = 7600. 3 jumps of 100 from 7300 reach 7600, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 3 skip-count steps of 100 as a total of 300.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 100s through four-digit numbers to reach the start.
Starting from and skip-counting up by 6 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 6 times lands on 8190. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 6 steps.
- After 6 steps the number is 8190.
Unknowns
- The starting number.
Constraints
- Counting up by 10 6 times means adding 10 a total of 6 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 8190.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 8130 + 10 = 8140, 8140 + 10 = 8150, 8150 + 10 = 8160, 8160 + 10 = 8170, 8170 + 10 = 8180, 8180 + 10 = 8190. 6 jumps of 10 from 8130 reach 8190, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 6 skip-count steps of 10 as a total of 60.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.
Starting from and skip-counting up by 6 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 100 6 times lands on 8400. Find the starting number.
Givens
- Each skip-count step adds 100.
- There are 6 steps.
- After 6 steps the number is 8400.
Unknowns
- The starting number.
Constraints
- Counting up by 100 6 times means adding 100 a total of 6 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 100 by counting back from 8400.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 7800 + 100 = 7900, 7900 + 100 = 8000, 8000 + 100 = 8100, 8100 + 100 = 8200, 8200 + 100 = 8300, 8300 + 100 = 8400. 6 jumps of 100 from 7800 reach 8400, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 6 skip-count steps of 100 as a total of 600.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 100s through four-digit numbers to reach the start.
Starting from and skip-counting up by 7 times, you reach . Find the number .
Show solution
1 · Understandwhat's really being asked
Starting from an unknown number and skip-counting up by 10 7 times lands on 9081. Find the starting number.
Givens
- Each skip-count step adds 10.
- There are 7 steps.
- After 7 steps the number is 9081.
Unknowns
- The starting number.
Constraints
- Counting up by 10 7 times means adding 10 a total of 7 times.
2 · Planchoose the strategy
#11 Work Backwards
The end result is given and we want the start, which is the classic signal to work backwards: undo each step of 10 by counting back from 9081.
3 · Execute2 carry out the plan
1Find the total amount added
2Count back from the ending number
4 · Reviewdoes it hold up?
Check forward: 9011 + 10 = 9021, 9021 + 10 = 9031, 9031 + 10 = 9041, 9041 + 10 = 9051, 9051 + 10 = 9061, 9061 + 10 = 9071, 9071 + 10 = 9081. 7 jumps of 10 from 9011 reach 9081, so the start is right.
Standardsmin grade 4
2.NBT.A.2Count within 1000, skip-count by 5s, 10s, and 100s — Recognizing 7 skip-count steps of 10 as a total of 70.4.NBT.A.2Read and write multi-digit whole numbers and compare using symbols — Counting back by 10s through four-digit numbers to reach the start.