30 free levels
Mathematics · Number Peaks
Decimal Harbor
Moor boats on a decimal pier and line up the fleet in order.
- Grades
- 4–6
- Levels
- 72 in 3 tracks
- Free
- 30 levels
- Session
- 5–15 minutes
What it is
Boats arrive with decimal numbers on their sails. Learners moor each boat at the right mark on a zoomable harbor number line, compare tenths, hundredths and thousandths, and line the fleet up in order. Equal decimals such as 0.4 and 0.40 can moor in either order.
What children learn
Decimal place value as position: tenths, hundredths and thousandths on a number line, decimal–fraction links, comparing decimals of different lengths (0.5 vs 0.45, 0.307 vs 0.37), equal decimals with trailing zeros, and ordering.
What it teaches
- Decimals to thousandths
- Decimals on a number line
How to play
Drag the boat along the pier or tap a mark; arrow keys move one mark, Page Up and Page Down move five, Enter moors. To order boats, drag them into berths, or select a boat and use the arrow keys to move it. Compare with the <, = and > buttons.
Plays with: Touch Mouse Keyboard
Accessibility
- Read-aloud on request
- Fully playable with a keyboard
- Calm mode with reduced motion
- No timers or time pressure
- Never relies on color alone
- Quiet mode turns off sound effects
Level maps
Tracks and levels
Each track is made for a grade range. Start anywhere that fits — you don't have to play the younger tracks first. As a guest, your stars are saved on this device.
Tenths Tide
Tenths on the pier, decimals past 1, equal decimals and first hundredths.
Grade 4
24 levels · 10 free
Tenths Tide
Tenths on the pier, decimals past 1, equal decimals and first hundredths. · Grade 4
- 1 Low Tide 1 ☆☆☆
- 2 Low Tide 2 ☆☆☆
- 3 Low Tide 3 ☆☆☆
- 4 Low Tide 4 ☆☆☆
- 5 Low Tide 5 ☆☆☆
- 6 Low Tide 6 ☆☆☆
- 7 Long Pier 1 ☆☆☆
- 8 Long Pier 2 ☆☆☆
- 9 Long Pier 3 ☆☆☆
- 10 Long Pier 4 ☆☆☆
- 11 Long Pier 5 Plan level
- 12 Long Pier 6 Plan level
- 13 Twin Moorings 1 Plan level
- 14 Twin Moorings 2 Plan level
- 15 Twin Moorings 3 Plan level
- 16 Twin Moorings 4 Plan level
- 17 Twin Moorings 5 Plan level
- 18 Twin Moorings 6 Plan level
- 19 Fine Marks 1 Plan level
- 20 Fine Marks 2 Plan level
- 21 Fine Marks 3 Plan level
- 22 Fine Marks 4 Plan level
- 23 Fine Marks 5 Plan level
- 24 Fine Marks 6 Plan level
Levels after 10 are part of a PlayOwl plan. Free levels, saving and basic reports stay free.
Hundredths Harbor
Hundredths on a zoomed pier, tricky comparisons and ordering with equal values.
4–5
24 levels · 10 free
Hundredths Harbor
Hundredths on a zoomed pier, tricky comparisons and ordering with equal values. · 4–5
- 1 Harbor Marks 1 ☆☆☆
- 2 Harbor Marks 2 ☆☆☆
- 3 Harbor Marks 3 ☆☆☆
- 4 Harbor Marks 4 ☆☆☆
- 5 Harbor Marks 5 ☆☆☆
- 6 Harbor Marks 6 ☆☆☆
- 7 Tricky Tides 1 ☆☆☆
- 8 Tricky Tides 2 ☆☆☆
- 9 Tricky Tides 3 ☆☆☆
- 10 Tricky Tides 4 ☆☆☆
- 11 Tricky Tides 5 Plan level
- 12 Tricky Tides 6 Plan level
- 13 Matching Masts 1 Plan level
- 14 Matching Masts 2 Plan level
- 15 Matching Masts 3 Plan level
- 16 Matching Masts 4 Plan level
- 17 Matching Masts 5 Plan level
- 18 Matching Masts 6 Plan level
- 19 Open Water 1 Plan level
- 20 Open Water 2 Plan level
- 21 Open Water 3 Plan level
- 22 Open Water 4 Plan level
- 23 Open Water 5 Plan level
- 24 Open Water 6 Plan level
Levels after 10 are part of a PlayOwl plan. Free levels, saving and basic reports stay free.
Thousandths Fleet
Thousandths, close comparisons and five-boat orderings past 1.
5–6
24 levels · 10 free
Thousandths Fleet
Thousandths, close comparisons and five-boat orderings past 1. · 5–6
- 1 Fine Tuning 1 ☆☆☆
- 2 Fine Tuning 2 ☆☆☆
- 3 Fine Tuning 3 ☆☆☆
- 4 Fine Tuning 4 ☆☆☆
- 5 Fine Tuning 5 ☆☆☆
- 6 Fine Tuning 6 ☆☆☆
- 7 Close Calls 1 ☆☆☆
- 8 Close Calls 2 ☆☆☆
- 9 Close Calls 3 ☆☆☆
- 10 Close Calls 4 ☆☆☆
- 11 Close Calls 5 Plan level
- 12 Close Calls 6 Plan level
- 13 Fleet Review 1 Plan level
- 14 Fleet Review 2 Plan level
- 15 Fleet Review 3 Plan level
- 16 Fleet Review 4 Plan level
- 17 Fleet Review 5 Plan level
- 18 Fleet Review 6 Plan level
- 19 Grand Regatta 1 Plan level
- 20 Grand Regatta 2 Plan level
- 21 Grand Regatta 3 Plan level
- 22 Grand Regatta 4 Plan level
- 23 Grand Regatta 5 Plan level
- 24 Grand Regatta 6 Plan level
Levels after 10 are part of a PlayOwl plan. Free levels, saving and basic reports stay free.
Off screen
Print & play
Paper activities that go with this game.
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