⚓ Luna's Math Quest
Decimal Docks
Decimal place value, comparing, add/subtract, and the link between fractions and decimals.
Decimal Places
How this station is declared (YAML)
id: dd-place title: Decimal Places icon: 🔬 board: dec-place bands: - 0 - 2 lesson: decimal-place concept: decimal-place
Lesson: Decimal Places — 4 steps
Tenths
Introduce the idea. Luna opens with the decgrid visual — a hundred-grid shading a decimal value (tenths/hundredths), across 2 narrated beats, so the concept is seen before it is ever practised.
What Luna says
- A decimal shows a part smaller than one. The point separates the whole from the part.
- This whole square is split into a hundred. Three shaded columns are three tenths — zero point three.
In the open config
id: tenths
label: Tenths
beats:
- say: ldp-1
caption: A decimal shows a part smaller than one. The point separates the whole from the part.
view:
kind: decgrid
key: d03
value: 0.3
- say: ldp-2
caption: This whole square is split into a hundred. Three shaded columns are three tenths — zero point three.
view:
kind: decgrid
key: d03
value: 0.3Preview
Hundredths
Worked example. Luna walks one case step by step with the decgrid view — a hundred-grid shading a decimal value (tenths/hundredths), turning the idea into a procedure a child can repeat.
What Luna says
- Each tiny square is one hundredth. Forty-five squares is zero point four five.
In the open config
id: hundredths
label: Hundredths
beats:
- say: ldp-3
caption: Each tiny square is one hundredth. Forty-five squares is zero point four five.
view:
kind: decgrid
key: d045
value: 0.45Preview
Same as ½
Worked example. Luna walks one case step by step with the decgrid view — a hundred-grid shading a decimal value (tenths/hundredths), turning the idea into a procedure a child can repeat.
What Luna says
- Decimals and fractions name the same part two ways. Zero point five is the same as one-half.
In the open config
id: convert
label: Same as ½
beats:
- say: ldp-4
caption: Decimals and fractions name the same part two ways. Zero point five is the same as one-half.
view:
kind: decgrid
key: d05
value: 0.5Preview
Your turn
Your turn. The lesson hands off to the practice board: the child now answers, applying what the decgrid visual — a hundred-grid shading a decimal value (tenths/hundredths) just showed.
What Luna says
- The first place after the point is tenths, the next is hundredths. You try!
In the open config
id: go
label: Your turn
beats:
- say: ldp-5
caption: The first place after the point is tenths, the next is hundredths. You try!
view:
kind: decgrid
key: d03b
value: 0.3Preview
Compare Decimals
How this station is declared (YAML)
id: dd-compare title: Compare Decimals icon: ⚖️ board: dec-compare bands: - 0 - 2 lesson: compare-decimals concept: compare-decimals
Lesson: Compare Decimals — 2 steps
Which is bigger
Introduce the idea. Luna opens with the compdec visual — two decimals aligned by place value for comparing, across 2 narrated beats, so the concept is seen before it is ever practised.
What Luna says
- To compare decimals, line up the points and look place by place. Which is bigger: zero point five, or zero point four five?
- Five tenths fills more than forty-five hundredths, so zero point five wins. Don't be fooled by extra digits!
In the open config
id: which
label: Which is bigger
beats:
- say: lcd-1
caption: "To compare decimals, line up the points and look place by place. Which is bigger: zero point five, or zero point four five?"
view:
kind: compdec
key: c5045
a: 0.5
b: 0.45
- say: lcd-2
caption: Five tenths fills more than forty-five hundredths, so zero point five wins. Don't be fooled by extra digits!
view:
kind: compdec
key: c5045
a: 0.5
b: 0.45Preview
Your turn
Your turn. The lesson hands off to the practice board: the child now answers, applying what the compdec visual — two decimals aligned by place value for comparing just showed.
What Luna says
- Compare the tenths first, then the hundredths. You try!
In the open config
id: go
label: Your turn
beats:
- say: lcd-3
caption: Compare the tenths first, then the hundredths. You try!
view:
kind: compdec
key: c7068
a: 0.7
b: 0.68Preview
Add & Subtract
How this station is declared (YAML)
id: dd-addsub title: Add & Subtract icon: ➕ board: dec-addsub bands: - 0 - 2 lesson: add-decimals concept: add-decimals
Lesson: Add & Subtract — 2 steps
Line up points
Introduce the idea. Luna opens with the adddec visual — adding two decimals, lined up on the decimal point, across 2 narrated beats, so the concept is seen before it is ever practised.
What Luna says
- To add decimals, line up the decimal points so tenths sit under tenths. One point two plus three point four.
- Then add just like whole numbers. One point two plus three point four is four point six.
In the open config
id: lineup
label: Line up points
beats:
- say: lad-1
caption: To add decimals, line up the decimal points so tenths sit under tenths. One point two plus three point four.
view:
kind: adddec
key: a1234
a: 1.2
b: 3.4
- say: lad-2
caption: Then add just like whole numbers. One point two plus three point four is four point six.
view:
kind: adddec
key: a1234
a: 1.2
b: 3.4Preview
Your turn
Your turn. The lesson hands off to the practice board: the child now answers, applying what the adddec visual — adding two decimals, lined up on the decimal point just showed.
What Luna says
- Line up the points, then add. You try!
In the open config
id: go
label: Your turn
beats:
- say: lad-3
caption: Line up the points, then add. You try!
view:
kind: adddec
key: a2513
a: 2.5
b: 1.3Preview
× and ÷ by 10, 100
How this station is declared (YAML)
id: dd-pow10 title: × and ÷ by 10, 100 icon: 🚀 board: dec-pow10 bands: - 0 - 2 lesson: decimal-pow10 concept: decimal-pow10
Lesson: × and ÷ by 10, 100 — 3 steps
× 10
Introduce the idea. Luna opens with the dechop visual — multiplying/dividing a decimal by 10/100 — the point hops places, across 2 narrated beats, so the concept is seen before it is ever practised.
What Luna says
- Multiplying by ten makes a number ten times bigger — the point hops one place to the right.
- So three point four times ten becomes thirty-four.
In the open config
id: times
label: × 10
beats:
- say: lpw-1
caption: Multiplying by ten makes a number ten times bigger — the point hops one place to the right.
view:
kind: dechop
key: hx
from: 3.4
factor: 10
op: ×
- say: lpw-2
caption: So three point four times ten becomes thirty-four.
view:
kind: dechop
key: hx
from: 3.4
factor: 10
op: ×Preview
÷ 10
Worked example. Luna walks one case step by step with the dechop view — multiplying/dividing a decimal by 10/100 — the point hops places, turning the idea into a procedure a child can repeat.
What Luna says
- Dividing by ten makes it ten times smaller — the point hops to the left.
In the open config
id: divide
label: ÷ 10
beats:
- say: lpw-3
caption: Dividing by ten makes it ten times smaller — the point hops to the left.
view:
kind: dechop
key: hd
from: 3.4
factor: 10
op: ÷Preview
Your turn
Your turn. The lesson hands off to the practice board: the child now answers, applying what the dechop visual — multiplying/dividing a decimal by 10/100 — the point hops places just showed.
What Luna says
- Times ten hops right, divide by ten hops left. By a hundred, hop twice! You try!
In the open config
id: go
label: Your turn
beats:
- say: lpw-4
caption: Times ten hops right, divide by ten hops left. By a hundred, hop twice! You try!
view:
kind: dechop
key: hx100
from: 3.4
factor: 100
op: ×Preview
Decimal × Whole
🚧 This activity is on the map and coming soon.
Fractions ↔ Decimals
How this station is declared (YAML)
id: dd-convert title: Fractions ↔ Decimals icon: 🔁 board: dec-convert bands: - 0 - 2 lesson: decimal-place concept: decimal-place
Lesson: Decimal Places — 4 steps
Tenths
Introduce the idea. Luna opens with the decgrid visual — a hundred-grid shading a decimal value (tenths/hundredths), across 2 narrated beats, so the concept is seen before it is ever practised.
What Luna says
- A decimal shows a part smaller than one. The point separates the whole from the part.
- This whole square is split into a hundred. Three shaded columns are three tenths — zero point three.
In the open config
id: tenths
label: Tenths
beats:
- say: ldp-1
caption: A decimal shows a part smaller than one. The point separates the whole from the part.
view:
kind: decgrid
key: d03
value: 0.3
- say: ldp-2
caption: This whole square is split into a hundred. Three shaded columns are three tenths — zero point three.
view:
kind: decgrid
key: d03
value: 0.3Preview
Hundredths
Worked example. Luna walks one case step by step with the decgrid view — a hundred-grid shading a decimal value (tenths/hundredths), turning the idea into a procedure a child can repeat.
What Luna says
- Each tiny square is one hundredth. Forty-five squares is zero point four five.
In the open config
id: hundredths
label: Hundredths
beats:
- say: ldp-3
caption: Each tiny square is one hundredth. Forty-five squares is zero point four five.
view:
kind: decgrid
key: d045
value: 0.45Preview
Same as ½
Worked example. Luna walks one case step by step with the decgrid view — a hundred-grid shading a decimal value (tenths/hundredths), turning the idea into a procedure a child can repeat.
What Luna says
- Decimals and fractions name the same part two ways. Zero point five is the same as one-half.
In the open config
id: convert
label: Same as ½
beats:
- say: ldp-4
caption: Decimals and fractions name the same part two ways. Zero point five is the same as one-half.
view:
kind: decgrid
key: d05
value: 0.5Preview
Your turn
Your turn. The lesson hands off to the practice board: the child now answers, applying what the decgrid visual — a hundred-grid shading a decimal value (tenths/hundredths) just showed.
What Luna says
- The first place after the point is tenths, the next is hundredths. You try!
In the open config
id: go
label: Your turn
beats:
- say: ldp-5
caption: The first place after the point is tenths, the next is hundredths. You try!
view:
kind: decgrid
key: d03b
value: 0.3Preview
