Sam received 87 dollars for his birthday. He went to a sporting goods store and bought a baseball glove, baseball, and bat. He had 10 dollars left over, how much did he spent on the baseball gear?

4 Answers
Aug 8, 2016

=77$

Explanation:

87-10
=77$

Aug 8, 2016

$77

Explanation:

This can be solved by color(blue)"subtracting" 10 from 87

That is 87 - 10 = 77

or by color(blue)"counting on" from 10 to 87

10to20=color(red)(10)
20to30=color(red)(10)
30to40=color(red)(10)
40to50=color(red)(10)
50to60=color(red)(10)
60to70=color(red)(10)
70to80=color(red)(10)

80to87=color(red)(7)

Total spent is then

= color(red)(10+10+10+10+10+10+10+7)=$77

Aug 8, 2016

He spent $77

Explanation:

Although the calculation is very easy, the purpose of this type of question is to be able to interpret 'word sums' and decide on a correct operation.

We are actually looking for "THE DIFFERENCE" between the amount of money he started with and the amount he had at the end.

87 - ? = 10

"DIFFERENCE" means subtract.

87 -10 = 77

He spent $77.

Aug 11, 2016

A slightly different way of dealing with subtraction.

$77

Explanation:

Received color(green)($87).

But color(green)($87) can be written as color(green)($77+$10)

After spending some money he had color(blue)($10" left").

color(red)("So he spent:")

color(green)($77+$10)color(blue)( - $10)

color(red)(=$77+0" "=" "$77)