Question

Lena's mother asked her to count the number of pennies in the penny jar. Her mother said I made seven stacks of six pennies each and there were four leftover pennies. When Lena counted she made nine stacks of five pennies each and two left.

Answer 1

Part a) 9*5+2

Part b) 7*6+4

Part c) Lena is correct

Part d) see the explanation

Explanation:

The complete question in the attached figure

Part a) Write a numerical expression to represent Lena’s way of counting

To represent Lena’s way of counting, multiply the number of stacks by the number of pennies in each stack plus the number of pennies left over

Let

x -----> the number of stacks

y ----> the number of pennies in each stack

z ----> the number of pennies left over

so

`xy+z`

we have

x=9 stacks

y=5 pennies

z=2 pennies

substitute

`9*5+2`

Part b) Write a numerical expression to represent her mother's way

To represent her mother’s way of counting, multiply the number of stacks by the number of pennies in each stack plus the number of pennies left over

Let

x -----> the number of stacks

y ----> the number of pennies in each stack

z ----> the number of pennies left over

so

`xy+z`

we have

x=7 stacks

y=6 pennies

z=4 pennies

substitute

`7*6+4`

Part c) Lena thinks her mother must have been working with fewer pennies than she was. Is Lena correct?

we have that

Lena’s expression

`9*5+2`

Simplify

`9*5+2=47`

Her mother’s expression

`7*6+4`

Simplify

`7*6+4=46`

therefore

Lena’s expression is more.

Lena is correct

Part d) Use a < , > , or = symbol to show how the two expressions compare

`9*5+2 > 7*6+4`

`47 > 46`

The number 47 is greater than the number 46

therefore

The symbol is " >"