Borrow-aware subtraction from 1-digit basics to 4-digit answers. 30 progressive levels.
Why this matters
Counting change, checking time left, comparing prices - subtraction answers how far apart two values are.
Levels Cleared
0%
Group 1
Count Down
Score 100 in 57s
1-digit - 1-digit
Reach Target
Reach 150 pts in 58s
2d - 1d (no borrow)
Last Problems
Last for 18 problems
2d - 1d (with borrow)
Last Time
Last for 43 seconds
Mixed 1d/2d - 1d
Beat The Clock
Get 12 correct in 57s
Mixed (mastery)
Group 2
Count Down
Score 115 in 54s
2d - round number
Reach Target
Reach 173 pts in 56s
2d - 2d (no borrow)
Last Problems
Last for 21 problems
2d - 2d (borrow ones)
Last Time
Last for 41 seconds
2d - 2d (any)
Beat The Clock
Get 14 correct in 54s
2d - 2d (mastery)
Group 3
Count Down
Score 130 in 51s
3d - 2d (no borrow)
Reach Target
Reach 195 pts in 54s
3d - 2d (borrow ones)
Last Problems
Last for 24 problems
3d - 2d (cascade borrow)
Last Time
Last for 39 seconds
3d - 2d (any)
Beat The Clock
Get 16 correct in 51s
3d - 2d (mastery)
Group 4
Count Down
Score 145 in 48s
3d - 3d (no borrow)
Reach Target
Reach 218 pts in 52s
3d - 3d (borrow ones)
Last Problems
Last for 27 problems
3d - 3d (cascade borrow)
Last Time
Last for 37 seconds
3d - 3d (any)
Beat The Clock
Get 18 correct in 48s
3d - 3d (mastery)
Group 5
Count Down
Score 160 in 45s
4d - 3d (no borrow)
Reach Target
Reach 240 pts in 50s
4d - 3d (borrow ones)
Last Problems
Last for 30 problems
4d - 3d (cascade borrow)
Last Time
Last for 35 seconds
4d - 3d (any)
Beat The Clock
Get 20 correct in 45s
4d - 3d (mastery)
Group 6
Count Down
Score 175 in 42s
4d - 4d (no borrow)
Reach Target
Reach 263 pts in 48s
4d - 4d (borrow ones)
Last Problems
Last for 33 problems
4d - 4d (half borrow)
Last Time
Last for 33 seconds
4d - 4d (any)
Beat The Clock
Get 22 correct in 42s
4d - 4d (mastery)