Arithmetic and fractions

Question 1

What does “number” could mean?

Answer 1

Real numbers: positive, negative, zero, fraction, decimal. Zero is the only number netiher positive or negative

Question 2

Integer

Answer 2

Include all positive & negative numbers that are not fraction.

Question 3

Which are the first positive integers?

Answer 3

1, 2, 3, 4, 5…

Question 4

Result of addition

Answer 4

sum

Question 5

Result of subtraction

Answer 5

difference

Question 6

Result of multiplication

Answer 6

product

Question 7

Result of division

Answer 7

quotient

Question 8

Mental math: addition of two digits

Answer 8

Treat digits separately

∆ 37 + 56 = (30 + 7) + (50 + 6 ) = 80 + 13 = 93

Question 9

Mental math: subtraction of two digits

Answer 9

We can simplify subtraction by adding the same numer to both terms

∆ 82 - 47 = ( 82 + 3 ) - ( 47 + 3 ) 85 - 50 = 35

Question 10

Absolute value on number line

Answer 10

Distance of number from origin

| x - 5 | = distance of x from +5

| x + 3 | = distance of x from -3

| x -1 | > 4 equals x < -3 or x >5

x | = distance of x from origin

Question 11

Order of operations

Answer 11

• G rouping symbols
• E xponents Multiplication &
• D ivision
• A ddition &
• S ubtraction

Be careful when translating to plain text (calculator text ie)

Multiplication and division are at the same level

Nested group symbols () and []: work from inside out

Question 12

Decimals equivalent notation

Answer 12

Represent negative powers of 10

Question 13

Operations with decimals

Answer 13

• Addition and subtraction: vertically
• Multiplication: count decimal digits and add them, multiply, place numer of decimal digits
• Power: same as multiplication
• Divide: slide decimal point to right to create whole number, and divide

Image: good hack!

Question 14

Round to any decimal place

Answer 14

When you are asked to round to a place, look only at the digit in the next place to the right.

∆ 65,_5_35 rounded to the nearest thousand is 66,000, you only looked at the 5 and that0s why you round up.

DO NOT DOUBLE ROUND

Question 16

Is 0 an integer?

Answer 16

It is. Neither positive or negative.

Question 17

Is 0 even or odd?

Answer 17

Even

Question 18

Is 0 positive or negative?

Answer 18

Neither

Question 19

Dies “non negative” include 0?

Answer 19

Yes: 0, 1, 2, 3, 4…

Question 20

Prime numbers principal characteristic

Answer 20

Have only 2 factors: itself and 1

Question 21

Prime numbers from 1-100

Answer 21

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97

Question 22

Is 1 a prime number?

Answer 22

No. It has only one factor.

Question 23

What are the prime even numbers?

Answer 23

Only 2

Question 24

factors facts

Answer 24

If A * B = C

A and B are factors of C

• 1 is a factor of every positive integer
• Every integer is a factor of itself

____________

If you divide an integer C by another integer B, and the result is another integer (remainder 0), then B is a factor of C.

Question 25

divisor facts

Answer 25

If C/A = B (B integer)

A is a divisor of C, because it divides evenly into C.

Everu factor is a divisor, every divisor is a factor

Question 26

multiple

Answer 26

Take any positive integer and multiply it by any whole number, the result is a multiple of the original number.

Question 27

How to know if a numer is divisible by 2?

Answer 27

Last digit should be even

Question 28

How to know if a numer is divisible by 5?

Answer 28

Last digit should be 5 or 0

Question 29

How to know if a numer is divisible by 4?

Answer 29

Last 2 digits should be divisible by 4.

Question 30

How to know if a numer is divisible by 3?

Answer 30

The sum of all digits should be divisible by 3

Question 31

How to know if a numer is divisible by 9?

Answer 31

The sum of all digits should be divisible by 9

Question 32

How to know if a numer is divisible by 6?

Answer 32

Must be divisible by 2 and by 3.

Any even number that is divisible by 3-