Menu

Interactive Bar

Google Services

Translate

Translate

Search

Search
  • Jarrow Cross C of E Primary School
‘Living and Learning’
Value in Everyone

Tuesday 2nd February

Visit TTR's and go on it for 10-15 minutes.

 

Today's learning will focus on estimating answers.

You MUST NOT calculate your answers accurately, unless a questions asks you to do so (to check your estimated answer) because it is asking you to ESTIMATE

 

What does it mean by 'estimating'/'estimate'? 

Estimating means to roughly calculate or judge an answer.

 

Although, estimating is a form of 'guessing', it has to be logical.

 

What does it mean by logical? 

Logical means sensible

 

Therefore, you must think carefully if your answer is sensible.
 

For example: For 73 + 43, I estimate the answer will be 80. This is not a sensible estimate because straight away we know that it is asking you to add 4 tens to 73 so the answer would be  at least, 110. 

 

A good way to estimate answers sensibly is through a strategy/method of rounding. You have already learnt about rounding in school. Remember the song we learnt (click the link): We will round you! - YouTube

 

For instance, if a question asks you to estimate the answer for: 154 + 72
When rounding to 10, we know that 154 rounds down to 150 (5 or more you raise the score) and 72 rounds down to 70 (4 or less you let it rest). Therefore, 150 + 70 = 220.

 

Another example is: 2,387 + 1,344
When rounding to the nearest 100, we know that 2,387 rounds up to 2,400 (50 or more you raise the score) and 1,344 rounds down to 1,300 (49 or less you let it rest). Therefore, 2,400 + 1,300 = 3,700.
or...

When rounding to the nearest 10, we know that 2,387 rounds up to 2,390 (5 or more you raise the score) and 1,344 rounds down to 1,340 (4 or less you let it rest). Therefore, 2,390 + 1,340 = 3, 730.

Which calculation do you think is the closest to the answer? Why might this be? Consider this when estimating your answers. 

 

Now, watch this video from the start because it recaps rounding further and also will help support your child with the layout of the questions: Aut4.7.3 - Estimate answers on Vimeo 

 

Now download and complete the worksheet below.

Top