Rounding Money

Overview

In this lesson 3 of 6, students practise rounding money amounts to the nearest dollar using a hands-on approach. They learn to decide whether to round up or down based on the number of cents.

Learning intentions

• WALT round currency amounts to the nearest dollar.
• WALT explain the reasoning behind rounding decisions using money language (dollars and cents).
• WALT use rounding strategies to make sensible estimates with money amounts.

Success criteria

• I can round a given amount to the nearest dollar accurately.
• I can explain whether I rounded up or down and why (based on cents).
• I can use a number line or visual cue to check my rounding.
• I can apply the rule correctly to a variety of amounts, including amounts with 0–99 cents.

Curriculum links

• Number and algebra: understanding whole numbers, place value, and rounding strategies.
• Measurement and money: using and interpreting amounts in everyday contexts (money).
• Mathematical thinking and reasoning: justifying answers and explaining strategies.
• Communication: using clear mathematical language to describe methods.

Lesson structure (30 minutes)

1. 0–4 min: Hook with quick talk Show 3 price cards (for example: $6.20, $6.50, $6.75). Ask: “Which ones are closest to $6 and which are closest to $7?” Students turn-and-talk, then share one reason.

2. 4–10 min: WALT model—hands-on rounding with cents Use real coins or paper “cents” discs (or place-value cards) to build amounts. Write an example: $8.34.

• Point out dollars vs cents.
• Teach the rule: look at the cents; if cents are 0–49, round down; if cents are 50–99, round up. Demonstrate with $8.50 rounding to $9 (round up) and $8.49 rounding to $8 (round down). Emphasise explaining: “The cents are 34, so it’s closer to 8 dollars.”

3. 10–18 min: Guided practice in pairs (worksheets + check method) Give students 6–8 rounding questions to complete in pairs. Require:

• Step 1: underline the cents.
• Step 2: decide down or up.
• Step 3: write the nearest dollar amount. Students then check using a small number line (0–10 dollars) or a teacher-provided rounding visual (a “<50 / ≥50” slider). Teacher circulates, listening for clear explanations.

4. 18–24 min: Reasoning challenge—short explanations Display four “mystery” amounts and ask students to choose the rounded answer and write a 1–2 sentence explanation:

• Example set: $12.01, $12.49, $12.50, $12.99 (students explain why two round differently). Do a quick class share of one correct explanation and one common misconception (for example, “50 rounds down” is wrong).

5. 24–28 min: Quick formative check (exit round) Each student answers 2 questions on mini whiteboards: one that should round down and one that should round up. Teacher quickly scans for accuracy and whether reasoning mentions cents and the “closer to” idea.

6. 28–30 min: Reflect and tidy Students state: “Today I learned to round money by…” and one thing that helps them decide up/down. Collect materials.

Resources

• Coin manipulatives (or paper copies) for dollars and cents
• Place-value cards or money “amount” cards (dollar part and cents part)
• Mini whiteboards and markers
• Number line posters (0–10 or 0–20 dollars) for visual checking
• “<50 / ≥50” rounding visual slider or card
• Short guided practice worksheet (6–8 items)
• Exit ticket slips (2 rounding questions)
• Answer key for teacher quick check
• Timer for pair discussion and written reasoning

Assessment

• Formative: teacher observation during paired practice, focusing on correct decision (up/down) and explanation using cents.
• Formative: mini whiteboard exit check (accuracy plus brief reasoning).
• Success criteria evidence: students can correctly round multiple amounts and articulate “because the cents are…” in their own words.

Differentiation

• Support: provide a visual “cents to decision” card (<50 down, ≥50 up) and a partially completed worked example; offer sentence stems such as “I rounded down because…” and “I rounded up because…”.
• Support: allow students to use number line checks with buddy support before finalising answers.
• Extension: include larger sums and more contexts, such as rounding $132.45 and $987.50 to the nearest dollar, and encourage checking using estimation.
• EAL/SEN: use consistent money vocabulary (dollars/cents/nearest) and model one verbal explanation repeatedly; provide bilingual support if available; reduce the number of questions while keeping the reasoning requirement.