Question

Berenika wants to buy 35 t-shirts. Each t-shirt costs £5.80. Berenika does the calculation 40 x 6 = 240to estimate the costs of 35 t-shirts. Explain how Berenika's calculation shows that the actual cost will be less than £240

Answer 1

The calculation 40 * 6 is rounded to the nearest whole number.

Remember with a number 5 and higher, round up and a number 4 and below, round down.

35 → 40

5.80 → 6

The calculation will be less then £240 because both numbers were rounded up. We can check:

35 * 5.80 = £203

240 > 203

Therefore, the actual cost will lower because the number of t-shirts bought and the cost per t-shirt was rounded up.