Question

estimate the perimeter of a school chalkboard, measuring 76 cm by 46 cm. Give your answer to the nearest ten​

Answer 1

Answer:

240 cm (to the nearest ten)

Step-by-step explanation:

perimeter of a rectangle = 2W + 2L

where W is the width and L is the length

To estimate the perimeter, first round the components to the nearest ten then carry out the calculation.

Given:

• width = 46 cm ≈ 50 cm (nearest ten)
• length = 76 cm ≈ 80 cm (nearest ten)

⇒ estimated perimeter = 2 x 50 + 2 x 80 = 100 + 160 = 260 cm

Alternatively, to calculate the actual perimeter and then round the answer to the nearest ten:

⇒ actual perimeter = 2 x 46 + 2 x 76 = 92 + 152 = 244 cm

⇒ perimeter = 240 cm (to the nearest ten)

Answer 2

Answer:

260

Step-by-step explanation:

76 rounded to 1 s.f. is 80

46 rounded to 1s.f. is 50

80+50+80+50= 260

Hope this helps!