Mathematics · Class 2 · Adding and Subtracting Stories · Term 1

Mental Math Strategies for Addition

Developing flexible strategies like doubling, near doubles, and making tens for faster calculation.

• CBSE Learning Outcomes
• CBSE: Mental Arithmetic - Class 2

About This Topic

Mental math strategies for addition give Class 2 students quick ways to find sums without pencil and paper. They practise doubling, such as 3 + 3 = 6; near doubles, like 7 + 8 = 14 + 1 = 15; and making tens, for example, 9 + 6 = 10 + 5 = 15. These build on number bonds to ten, helping students see why breaking larger numbers into smaller parts speeds up calculation and how known facts like ten plus five solve nine plus five.

This topic forms a core part of the CBSE Mathematics curriculum in the Adding and Subtracting Stories unit for Term 1. It develops mental arithmetic fluency, a key standard, and supports efficient strategies for single-digit plus double-digit sums. Students gain number sense, choosing the best method for each problem, which lays groundwork for subtraction and multi-digit work.

Active learning suits this topic perfectly. Games with counters, cards, or number lines let students test strategies hands-on, compare speeds with peers, and adjust methods instantly. This approach makes abstract ideas concrete, boosts confidence, and ensures strategies stick through joyful repetition.

Key Questions

1. Why is it helpful to break a large number into smaller parts before adding?
2. How does knowing ten plus five help us solve nine plus five?
3. Which strategy is most efficient when adding a single digit to a double digit number?

Learning Objectives

• Calculate sums of two-digit and one-digit numbers using doubling and near doubles strategies.
• Apply the 'making tens' strategy to solve addition problems involving sums up to 20.
• Compare the efficiency of different mental addition strategies for specific problem types.
• Explain how breaking down numbers aids in faster mental addition.

Before You Start

Number Bonds to 10

Why: Students need a strong understanding of how to make ten with different pairs of numbers to effectively use the 'making tens' strategy.

Addition Facts within 20

Why: Familiarity with basic addition facts helps students recognise doubles and near doubles more quickly.

Key Vocabulary

Doubling	Adding a number to itself, like 5 + 5. It is a quick way to find the sum of two equal numbers.
Near Doubles	Using a known double to solve a problem where the numbers are close, like knowing 6 + 6 = 12 to help solve 6 + 7.
Making Tens	Breaking apart one number to make a full ten with another number, then adding the remainder. For example, 8 + 5 becomes 8 + 2 + 3, which is 10 + 3.
Number Bonds	Understanding how numbers can be combined or broken apart to make other numbers, especially how to make ten.

Watch Out for These Misconceptions

Common Misconception

Always count up from the larger number on fingers.

What to Teach Instead

Strategies like making tens offer faster paths without full counting. Pair games with timers show quicker methods work, helping students build fluency and prefer flexible thinking over slow counting.

Common Misconception

Written addition rules apply exactly to mental maths.

What to Teach Instead

Mental strategies ignore column order and use number facts freely. Station activities let students try multiple ways, discovering through peer talk that commutative property speeds mental work.

Common Misconception

Doubling only for even numbers close together.

What to Teach Instead

Any two same numbers double, and near doubles adjust easily. Visuals like bead strings in relays clarify this, as students manipulate and see patterns emerge in group sharing.

Active Learning Ideas

Stations Rotation: Strategy Stations

Prepare three stations: doubling with paired dice, near doubles matching cards, making tens with ten frames and counters. Small groups spend 10 minutes at each, solving problems and noting their strategy. Groups share one new tip before rotating.

40 min·Small Groups

Pairs Game: Doubles Dash

Each pair gets number cards from 1 to 9. One student draws two cards, doubles if possible or uses near doubles, and explains. Partner verifies with counters. Switch roles after five turns, track scores for fastest correct sums.

25 min·Pairs

Whole Class: Making Tens Relay

Divide class into two teams. Call a sum like 8 + 7. First student runs to board, breaks into tens and ones, solves aloud. Next teammate continues with new sum. Winning team discusses strategies used.

30 min·Whole Class

Individual Challenge: Strategy Sort

Give students sum cards and three baskets labelled doubling, near doubles, making tens. They sort each sum into the best strategy basket and solve. Pairs then check and swap tips on tricky ones.

20 min·Individual

Real-World Connections

• A shopkeeper in a busy market in Delhi might quickly calculate the total cost of two items, say ₹8 and ₹5, by thinking '8 plus 2 is 10, then add the remaining 3 to get ₹15'.
• When packing lunch, a child might count out 7 biscuits and then add 5 more. They could use near doubles: 'I know 7 plus 7 is 14, so 7 plus 8 would be 15, and 7 plus 5 is just one less, so 13'.

Assessment Ideas

Quick Check

Present students with a series of addition problems on the board (e.g., 7 + 7, 6 + 8, 9 + 4). Ask them to write down the strategy they used for each and the answer. Observe which strategies they naturally gravitate towards.

Discussion Prompt

Pose the problem: 'Rohan has 9 marbles and Priya gives him 5 more. How many marbles does Rohan have now?' Ask students to share in pairs how they would solve this mentally. Then, ask a few pairs to explain their strategy to the class, focusing on how they 'made ten'.

Exit Ticket

Give each student a card with a problem like '5 + 6'. Ask them to write the answer and then circle the strategy they used: Doubling, Near Doubles, or Making Tens. They can also draw a quick picture to show their thinking.

Frequently Asked Questions

What are mental math strategies for Class 2 addition?

Key strategies include doubling for equal addends like 5 + 5 = 10, near doubles such as 4 + 5 = 8 + 1 = 9, and making tens like 9 + 4 = 10 + 3 = 13. These encourage breaking numbers into parts close to ten or known doubles, building speed and confidence for daily sums up to 20 or beyond.

How to teach making tens strategy effectively?

Use ten frames or counters to show 8 + 5 as 10 + 3. Students fill frames to ten first, then add remainder. Relay games reinforce this by having them explain aloud, while sorting cards helps practise independently, linking to number bonds.

Why break numbers into smaller parts for addition?

Breaking uses friendly numbers like tens or doubles, making sums easier and faster. For example, 19 + 6 becomes 20 + 5. This develops flexible thinking, as seen in CBSE standards, and prepares for larger numbers by strengthening mental shortcuts over rote counting.

How can active learning help students master mental addition strategies?

Active learning through games, stations, and relays engages students kinesthetically, making strategies memorable. They test methods with manipulatives, compete in pairs for speed, and discuss in groups why one works best. This builds automaticity, corrects errors on the spot, and turns practice into play, far better than worksheets alone.