Part 1 — Lessons (58)
1. Place Value to 10,000
Every digit in a number has a place value — its spot tells you how much it's worth.
In 4,275: the 4 means 4 thousands, the 2 means 2 hundreds, the 7 means 7 tens, the 5 means 5 ones.
- Thousands · Hundreds · Tens · Ones
- Read it as "four thousand, two hundred seventy-five."
Try this: What is the value of the 6 in 3,618? (Answer: 600.)
2. Understanding Fractions of a Quantity
What is a fraction of a quantity?
A fraction tells us about equal parts of a whole. To find a fraction of a number, we divide by the bottom number (denominator) and multiply by the top number (numerator).
For example, to find 3/4 of 20: first divide 20 by 4 to get 5 (that is one quarter), then multiply by 3 to get 15. So 3/4 of 20 = 15.
Tip: 'of' in maths usually means multiply. Practise with simple numbers first, then move to larger ones.3. Adding & Subtracting with Regrouping
When a column adds up to 10 or more, you carry to the next column. When you can't subtract, you borrow.
Example: 47 + 38. 7 + 8 = 15 → write 5, carry 1. Then 4 + 3 + 1 = 8. Answer: 85.
Tip: Line up the ones under the ones, tens under the tens. Neat columns prevent mistakes.
4. Perimeter and Area of Rectangles
Perimeter
The perimeter is the total distance around the outside of a shape. For a rectangle, add all four sides, or use 2 × (length + width).
Area
The area is the space inside a shape, measured in square units. For a rectangle, multiply length × width.
Example: a rectangle 8 cm long and 5 cm wide has a perimeter of 2×(8+5) = 26 cm and an area of 8×5 = 40 square cm.
5. Introduction to Fractions
A fraction shows part of a whole. The bottom number (denominator) is how many equal parts; the top (numerator) is how many you have.
In a pizza cut into 4 slices, eating 1 slice is 1/4.
- 1/2 is bigger than 1/4 — fewer parts means bigger pieces.
Try this: If you eat 2 of 4 slices, what fraction is that? (2/4, the same as 1/2.)