O1C1 Estimation

Estimating is to....

• find the exact answer

• find something close to the correct answer

• use an algorithm

Tags

CCSS.3.OA.D.8

When estimating 347+ 455 you should...

• Round both numbers to the nearest ten and add them mentally (i.e. 350+460)

• Line both numbers up and solve to find the answer

• Round both numbers to the nearest hundred and add them mentally

• Just do 300+400 and ignore the other numbers

Estimate my change.... I buy a $71 pair of runners, I give a $100 (2 x $50 notes) , my change will be about?

• $171

• $25

• $20

• $30

Tags

CCSS.3.NBT.A.2

CCSS.3.OA.D.8

Estimate the cost.... I buy 3 pencils for $1.95 each.

• 3 x $2 = $6

• 3 x $1.50 = $3.50

Tags

CCSS.5.NBT.B.7

Approximate... I ran 393m to my Grandpa's house, If i run back the total distance ran will be?

• 800m

• 600m

• 39.3m

• 750m

Tags

CCSS.3.NBT.A.2

CCSS.3.OA.D.8

Ms. Stilson has a handful of goldfish crackers. You estimate how many she is holding using low high estimation. What numbers do you use? (Remember, you still want to try to be accurate)

• 0 is too low and 50 is too high

• -10 is too low and 40 is too high

• 5 is too low and 30 is too high

• 0 is too low and 1000 is too high

Estimate the cost of 21 packs of screws each costing $2.90. ONLY round to the 10s place and type a dollar sign in before submitting! (i.e. $40, $50, $60, $70, $80)

James has worked out 31.5 × 49.6 and got the answer 156.24. Use estimation to check whether his answer is likely to be correct. Briefly explain if his answer is correct or not.

A box of matches contains 52 matches. Estimate the total number of matches in 8 boxes. Write your answer as a number rounded to the tens place (i.e. 290, 300, 310, 320, etc)

Rather than lining up subtraction problems, a more efficient way to subtract is to... (check all that apply)

• Count up (i.e. 100-57 is 43 because 57+43 is 100)

• Swap the numbers (i.e. 100-57 is the same as 57-100)

• Subtract 5 at a time until you get your answer (i.e. 100-5-5-5-5-5-5-5-5-5-2 would be 100-57)

• Round a difficult number (i.e. 57 can be estimated to be 60 as long as you subtract 3 from the end again)