Let’s go through each example using the CUBES strategy step by step.
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Example #1:
> Janet’s mom gave her $20 for the mall. She bought a Wetzel Pretzel for $4.55 and a pair of earrings for eight dollars. How much money did she spend in all?
Step 1:
C – Circle key numbers
- $4.55 (pretzel)
- “eight dollars” → write as 8
- ($20 is extra info — we’re asked how much she *spent*, not how much she has left)
Step 2:
U – Underline the question
→ “How much money did she spend in all?”
Step 3:
B – Box key words
→ “spend in all” means add
Step 4:
E – Evaluate steps, eliminate extra info
→ We only need to add what she spent: $4.55 + $8
→ Ignore the $20 — that’s what she started with, not what she spent.
Step 5:
S – Solve and check
→ $4.55 + $8.00 = $12.55
→ Check: Does it make sense? Yes — pretzel under $5, earrings $8, total around $12–$13. Makes sense.
✔ Final Answer for Example #1:
$12.55
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Example #2:
> The total cost of Peyton’s purchase was $18.27. How much change would she receive from a twenty dollar bill?
Step 1:
C – Circle key numbers
- $18.27 (cost)
- “twenty dollar bill” → 20
Step 2:
U – Underline the question
→ “How much change would she receive...”
Step 3:
B – Box key words
→ “change from” means subtract
Step 4:
E – Evaluate steps, eliminate extra info
→ No extra info here. Just subtract cost from amount paid.
Step 5:
S – Solve and check
→ $20.00 - $18.27 = ?
Let’s do the math carefully:
```
20.00
- 18.27
_______
1.73
```
Check: Add back → $18.27 + $1.73 = $20.00
✔
✔ Final Answer for Example #2:
$1.73
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Example #3:
> Ben weighs 7.6 kg. His older brother is 3 times as heavy. How much does his older brother weigh?
Step 1:
C – Circle key numbers
- 7.6 kg (Ben’s weight)
- 3 (times as heavy)
Step 2:
U – Underline the question
→ “How much does his older brother weigh?”
Step 3:
B – Box key words
→ “3 times as heavy” means multiply
Step 4:
E – Evaluate steps, eliminate extra info
→ No extra info. Just multiply Ben’s weight by 3.
Step 5:
S – Solve and check
→ 7.6 × 3
Break it down:
7 × 3 = 21
0.6 × 3 = 1.8
Total = 21 + 1.8 = 22.8
Or directly:
7.6
× 3
= 22.8
Check: Is 22.8 about 3 times 7.6?
7.6 + 7.6 = 15.2; 15.2 + 7.6 = 22.8
✔
✔ Final Answer for Example #3:
22.8 kg
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Final Answer:
Example #1: $12.55
Example #2: $1.73
Example #3: 22.8 kg
Parent Tip: Review the logic above to help your child master the concept of cube subtraction worksheet.
