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Number, NAP-A3-NC11

 
What is the best way to estimate the total cost of these three objects?

 
`$50 + $30 + $90`
 
`$50 + $30 + $100`
 
`$50 + $40 + $90`
 
`$50 + $40 + $100`

​

Show Answers Only

`$50 + $40 + $100`

Show Worked Solution

`text(Rounding to the nearest $10)`

`$54 + $36 + $98 ~~ $50 + $40 + $100`

 

Filed Under: Basic Concepts and Calculations, Basic Concepts and Calculations Tagged With: Band 7, smc-3143-70-Estimates, smc-676-70-Estimates

Number, NAP-B4-NC11

`sqrt (190)` is between

`9 and 12` `12 and 14` `14 and 20` `40 and 50`
 
 
 
 
Show Answers Only

`12 and 14`

Show Worked Solution
`12^2` `= 144`
`13^2` `= 169`
`14^2` `= 196`

 

`:.sqrt190\ text(is between 12 and 14.)`

Filed Under: Basic Concepts and Calculations, Basic Concepts and Calculations, Basic Concepts and Calculations Tagged With: Band 7, smc-3143-50-Square roots, smc-3143-70-Estimates, smc-3173-30-Square roots, smc-3173-70-Estimates (non calc), smc-890-30-Square roots, smc-890-70-Estimates (non calc)

Number, NAP-J3-NC03

Locky got a new car and recorded how many litres of petrol he put into the car over 4 weeks.

Week 1: 62.35 litres

Week 2: 58.65 litres

Week 3: 44.95 litres

Week 4: 53.75 litres

To estimate how many litres of petrol he put into his car over the 4 weeks, Locky rounded the weekly amounts to the nearest 10 litres and added them.

How much was Locky's estimate?

`240\ text(litres)` `230\ text(litres)` `210\ text(litres)` `200\ text(litres)`
 
 
 
 
Show Answers Only

`210\ text(litres)`

Show Worked Solution
`text{Estimate (after rounding)}` `= 60 + 60 + 40 + 50`
  `= 210\ text(litres)`

Filed Under: Basic Concepts and Calculations, Basic Concepts and Calculations Tagged With: Band 7, smc-3143-60-Rounding, smc-3143-70-Estimates, smc-676-60-Rounding, smc-676-70-Estimates

Number, NAP-G3-NC28

Which value of  `A`  is closest to the missing number in this equation?

`(A + 89.29) ÷ 5.12 = 48.4`

`− 80` `80` `130` `160` `250`
 
 
 
 
 
Show Answers Only

`160`

Show Worked Solution
`(A + 89.29) ÷ 5.12` `= 48.4`
`(A + 89.29)` `= 48.4 xx 5.12`
  `~~50 xx 5\ \ \ text{(using approximation)}`
  `~~ 250`

 

`:. A` `~~ 250 – 89.29`
  `~~250 – 90`
  `~~ 160`

Filed Under: Basic Concepts and Calculations, Basic Concepts and Calculations Tagged With: Band 9, smc-3143-70-Estimates, smc-676-70-Estimates

Number, NAP-H3-NC22

Lily made a mobile phone call that lasted 39 minutes.

Her mobile phone provider charges her 19 cents per minute for calls.

Lily estimated that the total cost of the phone call was about $8.

Lily's estimate was

 
less than the actual cost.
 
equal to the actual cost.
 
more than the actual cost.
Show Answers Only

`text(more than the actual cost.)`

Show Worked Solution

`text(Using slightly higher round numbers to get an)`

`text(estimate of the cost:)`

`text(40 minutes × 20 cents = $8)`

`:.\ text($8 estimate is more than the actual cost.)`

Filed Under: Basic Concepts and Calculations, Basic Concepts and Calculations Tagged With: Band 8, smc-3143-70-Estimates, smc-676-70-Estimates

Number, NAP-I3-NC19

Patrick wants to buy some cricket equipment.

The sports shop's prices of the equipment he wants is listed in the table below.
 

 
Patrick buys all 4 items.

Which of these gives the correct range for the cost of this equipment?

`$300 - $330` `$330 - $360` `$360 - $390` `$390 - $420`
 
 
 
 
Show Answers Only

`$360 – $390`

Show Worked Solution

`text(One strategy for getting an estimate is:)`

`$162.80 + $103.10 ~~ $265`

`$265 + $20 ~~ $285`

`$285 + $90 ~~ $375`

`:.\ text(Range is:)\ \ $360 – $390`

Filed Under: Basic Concepts and Calculations, Basic Concepts and Calculations Tagged With: Band 7, smc-3143-70-Estimates, smc-676-70-Estimates

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