Equivalent columns
A ratio table keeps the ratio constant; read across to find a needed value.
Why it works
Every column of a 2:3 table is still 2:3.
Ratios · Ratios · 1.5
Ratio tables.
A ratio table lists equivalent ratios in columns, scaling both parts by the same number each step. They make it easy to find a matching value. 2:3, 4:6, 6:9, 8:12.
See it work.
Equivalent ratios
Scale both parts together.
Every column is the same ratio as 2:3.
| first | 2 | 4 | 6 | 8 | 10 |
| second | 3 | 6 | 9 | 12 | 15 |
| base | ×2 | ×3 | ×4 | ×5 |
Watch the method
Ratio tables
Scale 2:3 by 4 → 8:12.
1
Scale the ratio
Multiply the base ratio 2:3 by 4.
Practice until it feels automatic.
Your turn
Work it out.
Type a number, e.g. 40.
streak 0
best 0
… =
The idea underneath.
From easy to tricky.
In a 2:4 ratio, if the first part is multiplied by 3, what is that part?
1
Scale the ratio
Multiply the base ratio 2:4 by 3. 2:4 × 3 = 6:12
In a 1:5 ratio, if the first part is multiplied by 4, what is that part?
1
Scale the ratio
Multiply the base ratio 1:5 by 4. 1:5 × 4 = 4:20
In a 4:4 ratio, if the second part is multiplied by 4, what is that part?
1
Scale the ratio
Multiply the base ratio 4:4 by 4. 4:4 × 4 = 16:16
Where students slip.
Trap
Scaling the parts by different amounts.
Fix
Each column scales BOTH parts the same.
Trap
Adding down a column.
Fix
Multiply both parts to scale.
Test yourself.
The Test
12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.
0/12Answered
How to answerType just the value. Formatting won't trip you up — we ignore spaces, capital letters, commas, and subscript style, so
t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).Core
Core (4)
C1
In a 2:5 ratio, if the second part is multiplied by 5, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
C2
In a 2:5 ratio, if the first part is multiplied by 4, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
C3
In a 5:3 ratio, if the second part is multiplied by 2, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
C4
In a 2:3 ratio, if the first part is multiplied by 5, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
Apply
Apply (4)
A1
In a 1:5 ratio, if the second part is multiplied by 3, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
A2
In a 2:5 ratio, if the first part is multiplied by 2, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
A3
In a 1:3 ratio, if the first part is multiplied by 3, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
A4
In a 3:2 ratio, if the second part is multiplied by 6, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
Extension
Extension (4)
E1
In a 5:3 ratio, if the second part is multiplied by 3, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
E2
In a 5:4 ratio, if the first part is multiplied by 4, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
E3
In a 3:3 ratio, if the second part is multiplied by 3, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.
E4
In a 4:3 ratio, if the first part is multiplied by 2, what is that part?
Need a hint?
- Multiply both parts by the column number.
- Read off the value you need.