Class 5 Maths — 20 skills

Lakhs and crores

Indian places: ones, tens, hundreds, thousands, ten-thousands, lakhs (1,00,000), ten-lakhs, crores.

Builds on: Place value to 99,999

Try it:

1. What is the value of the thousands digit in 73,95,873? → 5,000
2. What is the value of the lakhs digit in 23,15,177? → 3,00,000

Estimate by rounding

Round each number first, then calculate — a quick way to check if an answer is sensible.

Builds on: Round to the nearest 100 or 1000

Try it:

1. Estimate 704 + 580 by rounding each to the nearest 100. → 1300
2. Estimate 220 + 584 by rounding each to the nearest 100. → 800

HCF and LCM

HCF = the biggest number that divides both. LCM = the smallest number both divide into.

Builds on: Factors and multiples

Try it:

1. What is the LCM of 6 and 11? → 66
2. What is the HCF of 18 and 9? → 9

Prime and composite numbers

A prime has exactly two factors: 1 and itself. 1 is neither prime nor composite.

Builds on: Factors and multiples

Try it:

1. Which of these is a prime number? → 47

Compare fractions

Make the bottoms the same (or cross-multiply), then compare the tops.

Builds on: Equivalent fractions

Try it:

1. Choose the sign: 1/2 ☐ 7/9 → <
2. Choose the sign: 3/5 ☐ 3/5 → =

Add unlike fractions

Find a common bottom (the LCM), change both fractions, add the tops, then simplify.

Builds on: Add and subtract like fractions, HCF and LCM

Try it:

1. 1/8 + 4/6 = ? (simplest form) → 19/24
2. 1/2 + 3/6 = ? (simplest form) → 1

Fraction of a quantity

To find 3/4 of 20: find 1/4 (20 ÷ 4 = 5), then take 3 of them (3 × 5 = 15).

Builds on: Fraction of a number

Try it:

1. What is 2/6 of 12? → 4
2. What is 6/10 of 60? → 36

Add and subtract decimals

Line up the decimal points (add zeros if needed), then add or subtract like whole numbers.

Builds on: Money with rupees and paise

Try it:

1. 4.45 + 6.7 = ? → 11.15
2. 4.52 + 0.64 = ? → 5.16

Compare decimals

Compare digit by digit after the point — 0.5 is bigger than 0.45 because 5 tenths > 4 tenths.

Builds on: Add and subtract decimals

Try it:

1. Which is the smallest ? → 0.25
2. Which is the largest ? → 0.19

Percentages

Per cent means "out of 100". 50% = half, 25% = a quarter, 10% = one tenth.

Builds on: Fraction of a quantity

Try it:

1. What is 50% of 16? → 8
2. What is 20% of 20? → 4

Area and perimeter of squares

Square: perimeter = 4 × side; area = side × side.

Builds on: Area of a rectangle

Try it:

1. A square has sides of 16 cm. What is its perimeter (cm) ? → 64
2. A square has sides of 18 cm. What is its area (sq cm) ? → 324

Volume of a cuboid

Volume = length × breadth × height, counted in cubic units.

Builds on: Area of a rectangle

Try it:

1. A box is 9 cm × 9 cm × 4 cm. What is its volume in cubic cm? → 324
2. A box is 11 cm × 10 cm × 6 cm. What is its volume in cubic cm? → 660

Angles in a triangle

The three angles of any triangle add up to 180°.

Builds on: Kinds of angles

Try it:

1. Two angles of a triangle are 66° and 70°. What is the third angle? → 44
2. Two angles of a triangle are 100° and 30°. What is the third angle? → 50

Average (mean)

Add all the values, then divide by how many values there are.

Builds on: Division with remainders

Try it:

1. What is the average of 31, 31, 40? → 34
2. What is the average of 27, 28, 26, 43? → 31

Speed, distance and time

Distance = speed × time. Time = distance ÷ speed.

Builds on: 2-digit × 2-digit, Division with remainders

Try it:

1. A train covers 420 km at 70 km/h. How many hours does it take? → 6
2. A train covers 180 km at 45 km/h. How many hours does it take? → 4

Profit and loss

Profit = selling price − cost price. If the selling price is lower, it is a loss.

Builds on: 4-digit addition and subtraction

Try it:

1. A shopkeeper buys a toy for ₹470 and sells it for ₹483. What is the result? → profit of ₹13
2. A shopkeeper buys a toy for ₹457 and sells it for ₹531. What is the result? → profit of ₹74

Handshakes and pairs

Each of n people shakes hands with n − 1 others, but that counts every handshake twice: n × (n − 1) ÷ 2.

Builds on: 2-digit × 2-digit

Try it:

1. 3 friends each shake hands with every other friend once. How many handshakes? → 3
2. 15 friends each shake hands with every other friend once. How many handshakes? → 105

Count the squares

In an n × n grid there are n² small squares, (n−1)² 2×2 squares… add them all.

Builds on: Number patterns and rules

Calendar reasoning

Days repeat every 7. Count the days forward and find the remainder when divided by 7.

Builds on: Months and calendar

Try it:

1. If the 1st of a month is a Friday, what day is the 7th? → Thursday
2. If the 1st of a month is a Wednesday, what day is the 15th? → Wednesday

Digit puzzles

List the possibilities in order so you do not miss any.

Builds on: Tens and ones

Try it:

1. How many two-digit numbers have digits that add up to 11 ? → 8
2. How many two-digit numbers have digits that add up to 8 ? → 8