Mathematics
Grade5
Easy
Question
Estimate the product 617 × 84.
- 40000
- 42000
- 45000
- 48000
Hint:
The estimate value are round up or down value of the actual value. The actual product is hard to do mentally and it takes time but when we take compatible number for estimation is easy to calculate mentally and saves time. Here we are given estimate the product 617 × 84.
The correct answer is: 48000
Here we need to find the estimated product of 617 × 84.
Since ,the actual product of 617 × 84 is,
617 × 84 = 51,828
And it mentally hard to calculate the we are going to estimate this product and find the compatible numbers,
Now
617→600 , here 617 rounds to 600 as tens digit 1 < 5.
And,
84→80 , here 84 rounds down to 80 as one’s digit 4 < 5.
Both number are compatible now the product of these numbers are,
600 × 80 = 48000
So the estimated product after rounding each number so that it has only one non-zero digit is 48,000.
Therefore, the estimated product of 600 × 80 is 48000 , which is mentally easy to calculate.
The answer is 48000 (option (d)).
The estimated product is the rounded product of actual product. Just find the compatible number and rounded up or down and the product is like mentally easy to solve. Apply same methods in similar questions.
