Estimating, fair shares and area
Answers are for parents and teachers.
1
Estimate 52 + 38 + 27 + 14 by rounding to the nearest ten. Then find the exact sum.
Estimate: 50 + 40 + 30 + 10 = 130. Exact: 52 + 38 + 27 + 14 = 131.
2
Farida wants to buy a bag for 64 LE and shoes for 38 LE. She has 100 LE. Estimate, then check exactly. Is it enough?
Estimate: 60 + 40 = 100 LE, so it is close. Exact: 64 + 38 = 102 LE. No, 100 LE is not enough.
3
A jug holds 1 L. How many mL is 1/8 L, and how many mL is 3/4 L?
1/8 L = 1,000 ÷ 8 = 125 mL. 1/4 L = 250 mL, so 3/4 L = 3 × 250 = 750 mL.
4
A rectangular rug is 9 m long and 4 m wide. Find its area and perimeter.
Area: 9 × 4 = 36 square metres. Perimeter: 9 + 4 + 9 + 4 = 26 m.
5
A rectangle has area 56 square cm and width 7 cm. What is its length? What is its perimeter?
Length: 56 ÷ 7 = 8 cm. Perimeter: 8 + 7 + 8 + 7 = 30 cm.