Geometry and MeasuresUpper and Lower Bounds

Grade 5

Complete the rounding table:

Task on Entry - Rounding

1 dp 2 dp 1 sf 2 sf

32.743

456.736

3.4782

19.9287

12.371

0.05950.0600.060.060.1

121012.3712.4

202019.9319.9

3.533.483.5

460500456.74456.7

333032.7432.7

• The length of a piece of string has been rounded to 7cm.

• What is the shortest and longest it could have been before rounding?

7cm6cm 8cm

6.5cm 7.5cm

Upper and Lower Bounds

• The width of a football pitch is 76.2 yards, to one decimal place.

• What is the widest and narrowest the pitch could be?

76.2 yards76.1 yards 76.3 yards

76.15 yards 76.25 yards

Upper and Lower Bounds

• A roof tile weighs 54.23g, correct to 2 decimal places.

• What is the minimum possible weight of 30 tiles?

54.23g54.22g 54.24g

54.225g 54.235g

Upper and Lower Bounds

54.225 x 30

= 1626.75g

= 1.6kg (1dp)

A postcard measures 8cm by 6cm, to the nearest whole centimetre. What is:

a) Its smallest possible area?b) Its biggest possible area?

8cm

6cm

Applying Upper and Lower Bounds

A postcard measures 8cm by 6cm, to the nearest whole centimetre. What is:

a) Its smallest possible area?

= 7.5cm x 5.5cm= 41.25cm² (2dp)

8cm

6cm

Upper and Lower Bounds

A postcard measures 8cm by 6cm, to the nearest whole centimetre. What is:

b) Its biggest possible area?

= 8.5cm x 6.5cm= 55.25cm² (2dp)

8cm

6cm

Upper and Lower Bounds

Independent Task

Further Bounds

1.84cm

2.25cm

Further Bounds

Work out the maximum and minimum dimensions of the shape…

Further Bounds

Using these dimensions, work out the maximum and minimum values for the area

Further Bounds

Calculating the maximum possible error…

Further Bounds

Calculating the maximum possible error…

Independent Task

Further Bounds

Calculate the maximum and minimum dimensions

Further Bounds

Calculate all the possible volumes

Further Bounds

Calculate the maximum possible error…

Stretch and Challenge