IB Math Studies Yr 1 Name_________________________________ Date_______________

Unit 1 Study Guide

Steps to rounding numbers: “Circle-Check-Change”

1. Circle: circle the number in the place value you want to round to 2. Check: check the number to the right 3. Change: change the circled number

o If the number to the right is 5 or more:

o If the number to the right is less than five:

**Every number to the right of the rounded number becomes zeros!**

THREE RULES for Identifying Significant Figures

IB Math Studies Yr 1

Scientific Notation is a way of writing numbers that accommodates values too large or small to be conveniently written in standard decimal notation. .

A number written in scientific notation has the form: a x 10k, where 1 ≤ a < 10 and 𝑘 ∈ Ζ

Changing a number into scientific notation: Example: Write 625000000 in the form a x 10k, where 1 ≤ a < 10 and 𝑘 ∈ Ζ

1. Type the given number into the calculator

2. Click Mode, and select SCI Then hit enter twice Then hit 2nd Quit to go back to the home screen

3. Hit enter on the home screen

“E” means “x 10k” where k is the number after the E.

4. We rewrite the expression to get a final answer of:

6.25 x 108

Important Notes:

Sometimes, the number after the E is negative. Make sure to include the negative in the exponent!

As soon as you are done writing the number in scientific notation.

CHANGE YOUR CALCULATOR BACK TO NORMAL IN MODE FOR ANY OTHER QUESTION!

When you see this mentioned just think

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IB Math Studies Yr 1

Converting a number from scientific notation to standard form: Example: Write the following number without exponents: 5.65 x 104

1. Type the number in the calculator the exact way it is written.

2. Make sure your calculator is in NORMAL MODE (You check this by clicking Mode, and Normal should be highlighted) Click Mode, and select NORMAL Then hit enter twice Then hit 2nd Quit to go back to the home screen

3. Hit Enter, and copy the number.

One Exception: However!!!!

Sometimes the calculator cannot give a number to you as just a number, even in normal mode

Sometimes it gives you a number and automatically puts that number in scientific notation!

In the case you must know how to move the decimal

Rules:

If the exponent is POSITIVE (the number after the “E” you must move the decimal that many places to the RIGHT.

If the exponent is NEGAVTIVE (the number after the “E” you must move the decimal that many places to the LEFT.

IB Math Studies Yr 1

Approximate value = ROUNDED OR ESTIMATED VALUE

3 Rules of Percentage Error:

1. Your answer is always positive 2. Never round a percentage error

3. Always put a “%” as your units