Mathematics · Year 1 · Measurement and Comparison · Spring Term

Measuring Mass with Non-Standard Units

Using cubes or other small objects to measure the mass of items on a balance scale.

• National Curriculum Attainment Targets
• KS1: Mathematics - Measurement

About This Topic

In Year 1 Mathematics, measuring mass with non-standard units introduces children to comparing weights using a balance scale and identical objects like cubes, counters, or buttons. Students place items on each side of the scale, note which tips lower to identify the heavier object, and count units to find equivalents for classroom items such as a pencil case, book, or toy car. This practical work matches KS1 Measurement objectives in the UK National Curriculum, focusing on fair comparisons and building foundational skills for later standard units.

Children address key questions by explaining scale function, constructing methods like repeated balancing, and justifying uniform units for reliable results. Activities encourage use of terms like heavier, lighter, balances, and same mass, while linking to real-life contexts such as sorting groceries or playground toys. These experiences develop precision, prediction, and justification skills essential for mathematical thinking.

Active learning suits this topic perfectly. Students handle scales and units directly, test predictions through trial and collaboration, and resolve errors via group discussion. Such approaches make mass concepts concrete, boost engagement, and ensure deeper retention than passive instruction.

Key Questions

1. Explain how a balance scale helps us compare weights.
2. Construct a method to find out how many blocks weigh the same as your pencil case.
3. Justify why we need to use the same type of unit when measuring mass.

Learning Objectives

• Compare the mass of two objects using a balance scale and non-standard units.
• Construct a method to determine the mass of an object by counting non-standard units.
• Explain how a balance scale indicates which object has greater mass.
• Justify the need for using identical non-standard units when measuring mass.

Before You Start

Comparing Sizes

Why: Students need to be able to visually compare objects based on size before they can compare them based on mass.

Counting to 20

Why: Students need to be able to count accurately to determine how many non-standard units are needed to balance an object.

Key Vocabulary

Mass	Mass is a measure of how much 'stuff' is in an object. We compare mass to see if something is heavier or lighter.
Balance scale	A tool with two pans that helps us compare the mass of two objects. The side that tips down holds the heavier object.
Heavier	An object is heavier if it has more mass. On a balance scale, the heavier object's side will tip down.
Lighter	An object is lighter if it has less mass. On a balance scale, the lighter object's side will tip up.
Same mass	Two objects have the same mass if they balance perfectly on a balance scale, meaning neither side tips.

Watch Out for These Misconceptions

Common Misconception

Bigger objects are always heavier.

What to Teach Instead

A large feather balances fewer cubes than a small stone. Hands-on balancing of varied sizes reveals mass differs from size; peer predictions and tests correct this through shared surprises and discussions.

Common Misconception

Any small objects work as units.

What to Teach Instead

Mixing cubes and buttons yields inconsistent counts for the same item. Demonstrating repeats with uniform units shows reliability; group trials highlight errors, prompting justification talks.

Common Misconception

Balance scale measures size or length.

What to Teach Instead

Same-sized boxes balance different cube counts if masses vary. Active exploration with disguised items builds understanding of mass focus; collaborative sorting reinforces the distinction.

Active Learning Ideas

Stations Rotation: Balance Challenges

Prepare four stations with balance scales, cubes, and objects like erasers, books, and fruits. Small groups rotate every 10 minutes, predict outcomes, balance items, and record unit counts. End with a class share of surprising results.

45 min·Small Groups

Pairs: Pencil Case Match

Provide cubes and scales. Pairs balance their pencil case against cubes, count the matching number, then swap cases to verify partner's count. Discuss why same cubes ensure fairness.

25 min·Pairs

Whole Class: Prediction Tournament

Display paired objects. Class votes on heavier item, tests on central scale, and tallies correct predictions. Award points to teams for accuracy and explanations.

30 min·Whole Class

Individual: Mass Hunt Journal

Children select five classroom items, sketch them, predict cube units needed, and measure using a personal scale. They reflect on matches versus predictions.

20 min·Individual

Real-World Connections

• Market vendors use balance scales to weigh produce like apples or potatoes, ensuring customers receive the correct amount for the price.
• A baker uses scales to measure ingredients like flour and sugar, ensuring consistency in recipes for cakes and bread.
• Children's toy stores often have balance scales for play, allowing young shoppers to compare the weight of different toys.

Assessment Ideas

Quick Check

Present students with a balance scale and two different classroom objects (e.g., an eraser and a book). Ask: 'Which object do you predict is heavier? Use the scale to check. Now, use 5 cubes to measure the eraser. How many cubes balance the eraser?'

Discussion Prompt

Show students two sets of blocks measuring the mass of the same object, but one set uses large blocks and the other uses small blocks. Ask: 'Why does one set of blocks need more items than the other to balance the pencil case? What should we do to make sure our measurements are fair and accurate?'

Exit Ticket

Give each student a small card. Ask them to draw a picture of a balance scale with two objects on it. They should circle the heavier object and write one sentence explaining why they chose that one.

Frequently Asked Questions

How do I introduce balance scales to Year 1?

Start with familiar objects like hands or toys on each side, asking children to predict and observe tips. Model vocabulary: heavier, lighter, balances. Follow with guided pairs practice using cubes, ensuring all handle scales safely. This builds confidence before independent measurement, aligning with curriculum progression.

What non-standard units work best for mass?

Use identical cubes, counters, or linking blocks for uniformity. Avoid loose items like peas that roll. Provide 20-50 per group. These allow repeatable counts, help justify fairness, and connect to classroom resources, making activities accessible and low-prep.

How to address justifying same units?

After mixed-unit trials showing varying counts, repeat with uniform cubes for consistent results. Children explain in pairs why sameness matters for fair comparison. plenary discussions reinforce this, using drawings or tallies to record thoughts and link to key questions.

How can active learning help Year 1 measure mass?

Active methods like rotating stations and pair challenges let children manipulate scales, test predictions, and collaborate on counts, turning abstract mass into tangible experiences. Group talks correct errors instantly, while recording builds reflection. This engagement deepens understanding, boosts confidence, and matches kinesthetic needs of young learners over worksheets.