# FORM ONE MATHEMATICS STUDY NOTES TOPIC 4-6.

**TOPIC 4: UNITS**

**TOPIC 5: APPROXIMATIONS**

Measurements can be rounded to a certain number of significant figures.Approximation- is a process of rounding numbers to a certain degree of accuracy.A number can be rounded to a certain required place value such as to the nearest ten, hundred, and thousand

The Knowledge of Rounding Off of Numbers in Computations Involving Large Numbers and Small Numbers

Use the knowledge of rounding off of numbers in computations involving large numbers and small numbers

Approximation
can be used in operation to check whether a calculation is correct or
not, i.e in addition, subtraction, multiplication and divisione.g 446 x
45 = 20 070

The
above calculation can be checked quickly whether it is correct or not
by rounding each number to 1 significant figure and then multiply i.e
400 x 50 = 20 000

Therefore,
the approximation of 20 000 is close to 20 0070 is correct.Before
carrying an operation, each number in a calculation is rounded to 1
significant figure

Example 5

Find the approximate value of

Example 6

A
school trip of 32 people went to a tour, which costs a transport fee of
580/- each people. What was the approximate total transport cost?

**Solution**

32 × 580 ≈30×600 = 18 000

**The approximate transport cost was 18 000/-**

**TOPIC 6: GEOMETRY**

**Points and Lines**

A Circle

Draw a circle

To make a circle: Draw a curve that is "radius" away from a central point.

And so:All points are the same distance from the center.

You
can draw it yourself:Put a pin in a board, put a loop of string around
it, and insert a pencil into the loop. Keep the string stretched and
draw the circle!

Different Parts of a Circle

Describe different parts of a circle

The

**radius**of the circle is a straight line drawn from the center to theboundaryline or the circumference. The plural of the word radius is**radii**.
The

**diameter**is the line crossing the circle and passing through the center. It is the twice of the length of the radius.
The

**circumference**of a circle is theboundaryline or theperimeterof the circle.
An

**arc**is a part of thecircumferencebetween two points or acontinuouspiece of a circle. The shorter arc betweenandis called the**minor arc**. The longer arc betweenandis called the**major arc**.
The

**chord**is a straight line joining two points on thecircumferencepoints of a circle. The diameter is a special kind of the chord passing through the center.
A

**semi-circle**is an arc which is half of thecircumference.
A

**tangent**is a straight line which touches the circle. It does not cut thecircumference. The point at which it touches, is called the**point of contact**.

**FORM ONE MATHEMATICS OTHER TOPICS**

**FORM ONE MATHEMATICS TOPIC 1-3.**

**FORM ONE MATHEMATICS STUDY NOTES TOPIC 4-6.**

**FORM ONE MATHEMATICS STUDY NOTES TOPIC 7-9.**

**FORM ONE MATHEMATICS STUDY NOTES TOPIC 10-11.**

**O'LEVEL MATHEMATICS NOTES**

**FORM ONE MATHEMATICS STUDY NOTES****FORM TWO MATHEMATICS STUDY NOTES****FORM THREE MATHEMATICS STUDY NOTES****FORM FOUR MATHEMATICS STUDY NOTES**
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