Estimation

Estimation

Mr Lochab

Multiple Choice

Estimate this persons age?

• 10-15

• 15-20

• 20-30

• 35-45

Multiple Choice

Estimate the age?

• 8-12

• 18-24

• 38-45

• 60+

Multiple Choice

Estimate the age?

• 8-12

• 18-24

• 38-45

• 60+

Multiple Choice

Estimate the age?

• 8-12

• 18-24

• 38-45

• 60+

Multiple Choice

Estimate the age?

• 8-12

• 18-24

• 38-45

• 60+

Only Joking, I am 36

• I am 36 and 19 days

• I am 36, 19 days and 16 hours

• I am 36, 19 days, 16 hours and 12 minutes

• I am 36, 19 days, 16 hours and 12 minutes, and 43 seconds

I am 36

• It tells you enough about me.

• Informative

• Approximate

• Estimate

Open Ended

How old are you?

Give me enough information that tells me you are in year 10, without being too precise that the information you give me is still relavent.

Estimation Calculations

• DO NOT ANSWER EXACT

• Round the number to 1 SF

• Quick mental Calculation

• If you can, check and compare

Multiple Choice

Estimate 20,132 + 10,320

What calculation should you do?

• 20,000 + 10,000

• 20,132 + 10,320

• 20,132 x 10,320

Multiple Choice

Estimate 20,132 + 10,320

Estimate?

• 30,000

• 30452

• 30

Multiple Choice

Estimate 20,132 + 10,320

The exact answer is 30,452, Our estimate was 30,000. This is an..

• Overestimate

• Underestimate

• Exact answer

Multiple Choice

Estimate £13.07 - £4.99

What is the correct calculations we need to do to ESTIMATE

• £13.07 - £4.99

• £13 - £4

• £13 - £5

• £10 - 0

Multiple Choice

39 people go to a gig and each pay £9.95 for a ticket. What would be a suitable calculation to do for this estimate?

• 39 x £9.95

• 39 x 9.95

• 40 x £10

Multiple Choice

39 people go to a gig and each pay £9.95 for a ticket.

Both of these numbers we have rounded up. Our answer of £400 is an

• Overestimate

• Underestimate

• Exact answer

Fill in the Blank

Step 1) Round these numbers to 1 S.F

48.7 rounds to

Fill in the Blank

Step 1) Round these numbers to 1 S.F

61.2 rounds to

Fill in the Blank

Step 1) Round these numbers to 1 S.F

11.3 rounds to

Multiple Choice

Step 2) Our calculation is now

 $\frac{50\ \times60}{10}$  
We can now calculate this quickly. 

• 506

• 3000

• 300

• 11

Fill in the Blank

Our estimate is 300.

Using a calculator (or google) what is the exact answer?

Fill in the Blank

Our estimate is 300.

The exact answer is 263.755752.

Is our answer an over or under estimate?

Fill in the Blank

Estimate $3.9^2$  

Fill in the Blank

Estimate $3.9^2$  

The correct answer is 16 and it is an ______ estimate

Fill in the Blank

Estimate $5.03^2$  

Fill in the Blank

Estimate $5.03^2$  

The correct answer is 25 and it is an _____ estimate

Past Exam Paper Questions

• Be Brave, you got this

• Round them down mentally

• Once rounded, you can caluclate (although practice mental maths)

• Once you have done so, do check your exact answer.