Docstoc

Using-spreadsheets-to-solve-problems

Document Sample
Using-spreadsheets-to-solve-problems Powered By Docstoc
					Using spreadsheets to solve problems
Numeracy focus
Problems involving 'real life' money or measures

Learning objectives
· To use a spreadsheet to solve simple number problems · To translate written problems into numerical operations · To represent number problems in algebraic terms

Resources
Set up the large display if available. Make copies of the Number Problems sheet for this lesson. There is a simpler version: Number Problems (2).

Revision / oral
Warm up with problems presented orally, for children to extract the mathematics: 'If I drive 3 miles each way to school every day, how far is that in a week?' Review the formulas used in the last lesson. Ask for examples of multiplication and division, then examples involving more than 2 operands:

Recap how we find the percentage of an amount. What is 80% of 100, of 200, of 520, of 20? Can pupils suggest the formula?

Main activity
Introduce the Number Problems sheet. Record the result in the 'answer' column in the 'Percentage' section: write the formula in column C or D. Remind pupils to think through the mathematics first, then build the formula. Reinforce the need for entering correct values, i.e. to two decimal places when working with money (2.5 or 2.50 for £2.50, 0.43 for 43 pence). Give the opportunity to clarify any point of the set task. Decide whether they should check work manually, or use calculators.

Support
The simpler sheet involves less complex calculations. Check that pupils get the subtraction the right way round in (2). Check that money is correctly entered, with decimal points, in (5) and (6).

Extension
Ask pupils to devise their own problem using at least two operators.

Page 1/6 NGfL, Kent Advisory Service 29/11/09

Plenary
Review the formulas which the children have used. Are there different ways of getting the answers? Mental arithmetic questions: the answer is given, and the pupil must suggest a formula to find the answer. Include all four rules of number.

Ask, 'Make up one of your own. Your answer must be 15. How many different operators can you use?'

Page 2/6 NGfL, Kent Advisory Service 29/11/09

Name: _______________________

Date: ________________

Number problems
Read the problem. Record the calculation and answer. Then show how you would work out the answer on a spreadsheet by entering a formula. Easy example Beth wants to send invitations to 31 friends. She only has 15 cards. How many more does she need?

31 – 15 = 16
C =A1-B1

A 1
1.

B 31 15

Paul bought 24 trays each holding 144 apples. How many apples did he buy?

A 1
2.

B

C

Annie loved to drink Coke. She drank 7 cans each day for 8 weeks. How many cans did she drink altogether?

A 1
3.

B

C

D

A flower seller bought flowers for Mothers Day. He bought 36 boxes of 80 flowers. How many flowers did he have?

A 1
He put 4 flowers in each bunch. How many bunches did he make?

B

C

C 1
4.

D

E

A dressmaker bought a 60m roll of fabric for £2 per metre. She cut it into 150cm lengths. How many lengths did she have?

A 1

B

C

D

Page 3/6 NGfL, Kent Advisory Service 29/11/09

She sold each piece for £2.50. How much money did she receive?

D 1
How much profit did she make?

E

F

F 1
Percentages

G

H

Show how you would work these out on a spreadsheet. Use columns A, B, C (and D if necessary). Write your answer in the column on the right. 1. Jane scored 21 out of a possible 75. What percentage did she get?

A 1
2.

B

C

D

Answer

Jane increases her score by 4 marks a week for the next 7 weeks. Work out her percentage for each week.

A 2 3 4 5 6 7 8
3.

B

C

D

Answer

Wilbur wanted a new jacket costing £56. He waited until he saw it in the sale marked 25% off. How much did he pay? How much did Wilbur save by waiting for the sale?

A 1 2

B

C

D

Answer

Page 4/6 NGfL, Kent Advisory Service 29/11/09

Name: _______________________

Date: ________________

Number problems (2)
Read the problem. Record the calculation and answer. Then show how you would work out the answer on a spreadsheet by entering a formula. Easy example Beth wants to send invitations to 31 friends. 31 – 15 = 16 She only has 15 cards. How many more does she need?

A 1
1.

B 31 15

C =A1-B1

Maxine bought 18 oranges and 24 apples. How many pieces of fruit did she buy?

A 1
2.

B

C

Children in Mrs Smith’s class have 18 cats and 23 dogs. How many more dogs are there than cats?

A 1
3.

B

C

Jack has 3 sausages for breakfast every day. How many does he eat in a week?

A 1
4.

B

C

Eddie had 20 flowers. He put 5 flowers in each bunch. How many bunches did he make?

C 1
5.

D

E

Sarah sells tickets for a show. People order 2 for Friday, 16 for Saturday and 5 for Sunday. How many tickets are ordered?

A 1

B

C

D

Page 5/6 NGfL, Kent Advisory Service 29/11/09

13 tickets are not collected. So how many has she actually sold?

D 1

E

F

The tickets are £4.50 each. How much does Sarah take?

F 1
6.

G

H

It’s Sam’s birthday. He has £5 from Auntie Jan, £6.50 from Auntie Pam and £3.45 from Uncle Stan. How much does he get altogether?

A 1

B

C

D

Sam spends £10.02. How much is left?

D 1

E

F

Page 6/6 NGfL, Kent Advisory Service 29/11/09


				
DOCUMENT INFO
Shared By:
Tags: Using, -spre
Stats:
views:42
posted:11/29/2009
language:English
pages:6
Description: Using-spreadsheets-to-solve-problems