# Binary Numbers ### Clues

```Across
1. Binary can be used to store text, sound, instructions and _________.
4. On a cd this area is counted as a zero valuable.
5. Binary data is easy and ________ to read.
8. Eight binary digits
9. CD Drives use a _______ to read cds.
10. A number system consisting of just two states
Down
2. The code system used by shipping and telegraphs.
3. Four binary digits
6. One single binary digit
7. The input ________ to a computer system is not very stable.

Printable Google Docs Version```

### Decimal to Binary Conversion

Let’s suppose we are trying to find the binary for the decimal number 75.

Step 1

### Step 1 – Write the 128 to 1 numbers

Starting on the right hand side, write down the numbers 1, 2,4,8 etc, doubling each time until you reach 128.

Remember smallest number at the right hand side!!! Step 2

### Step 2 – Cross out the unused numbers

Keeping only the numbers that you need to add up to your decimal number, cross out all other numbers. Step 3

### Step 3 – Write the ones or zeros

Under each number write a 1 if there is a number and a zero if you crossed out the number. Put the numbers all together and you have your binary number! Binary to decimal Conversion

Let’s suppose we are trying to find the decimal for the binary number 01101011.

Step 1

### Step 1 – Write the 128 to 1 numbers

Starting on the right hand side, write down the numbers 1, 2,4,8 etc, doubling each time until you reach 128.

Remember smallest number at the right hand side!!! Step 2

### Step 2 – Write the ones and zeros below the numbers Step 3

### Step 3 – Add up all the numbers with 1s below them to find your decimal number Decimal to Binary

Try converting these decimal numbers to binary!

a. 45

b. 12

c. 111

d. 255

e. 0

Binary to Decimal

Try converting these binary numbers to decimal

f. 11101101

g. 00010010

h. 10101010

i. 00101100

j. 10111010

Log on to Google Classroom and fill out your learning log for the lesson!

Complete the binary numbers review quiz  on QuizMaster

Kahoot

Have a go at this plenary as a class

### Worksheet Generator

You can use this online worksheet generator to create more worksheets to practice converting from Denary to Binary and back again!