Question

A school has $15,000 to spend on computer monitors. The school plans to purchase 200 monitors for $89 each. A teacher completes the calculations below and concludes that the school has enough money to buy the monitors. 200 × 89 = (200 × 8) + (200 × 9) = 1,600 + 1,800 = 3,400

Answer 1

Since the budget of the school is $15,000, the school does not have enough money to buy the monitors

Explanation:

The school plans to purchase 200 monitors for $89 each.

This is the calculation of the teacher

200 × 89 = (200 × 8) + (200 × 9) = 1,600 + 1,800 = 3,400

The teacher's calculation is wrong

The correct calculation using Distributive property is

a(b + c) = ab + ac

200 × 89 = 200(80) + 200(9)

Because 80 + 9 = 89

Hence,

200 × $89 = 16000 + 1800

= $17,800

Since the budget of the school is $15,000, the school does not have enough money to buy the monitors

$17, 800 ≠ $15,000