**Use properties to find the sum or product. **

**93+(68+7)**

**5x23x2**

**8x51**

**34+0+18+26**

**6x107**

Thanks!!

Guest Jun 27, 2017

#1**+2 **

1. \(93+(68+7)=93+75=168\)

2. \(5*23*2=23*10=230\)

Although calculating in this fashion does not adhere to the order of operations, calculating it this way makes it easier mentally. I can use this method because of the commutative property of multiplication, which states that multiplication can be done in any order

3. \(8*51=408\)

4. \(34+0+18+26=34+18+26=52+26=78\)

5. \(6*107=642\)

Except for #2, I use order of operations to calculate the sum or product. For number 2, I utilized the commutative property of multiplication.

TheXSquaredFactor
Jun 27, 2017

#2**+2 **

If by "use properties" you mean find a way to do these in your head, here's my take:

93 + 68 + 7 The 93 and the 7 sum to 100

= 100 + 68

= 168

5 * 23 * 2 5 and 2 multiply to 10

= 10 * 23 To multiply by 10, move the decimal point right one position.

= 230

8 * 51

= 8 * (50 + 1)

= 8 * 50 + 8 * 1

= 8 * 5 * 10 + 8 * 1

= 40 * 10 + 8

= 400 + 8

= 408

34 + 0 + 18 + 26 The 34 and 26 sum to 60

= 60 + 18

= 78

6 * 107

= 6 * (100 + 7)

= 6 * 100 + 6 * 7

= 600 + 42

= 642

I only used the calculator to check these!

Also...here is a question for X^{2} ....why did you say that calculating in this fashion doesn't adhere to the order of operations ?

hectictar
Jun 27, 2017

#3**+2 **

Well, for #2, I calculated in the exact same manner as you did. I multiplied 5 by 2 first. However, order of operations says that you always calculate from left to right. I didn't do that.

I guess that note causes more confusion that what is intended...

TheXSquaredFactor
Jun 27, 2017