Mathematics
Grade5
Easy
Question
Estimate. 22 × 12. Estimate is an overestimate or under estimate.
- 30 (over estimate)
- 200(under estimate)
- 20(over estimate)
- 300(under estimate)
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 wants estimate product 22 x 12 which is overestimated or under estimate.
The correct answer is: 200(under estimate)
Here we need to find the estimated product of 22 x 12. Which is overestimate or underestimate.
Since ,the actual product of 22 x 12 is,
22 x 12 = 264
And it mentally hard to calculate the we are going to estimate this product and find the compatible numbers,
Now
22 → 20 , here the 22 is rounded down to 20.
And,
12 → 10, here 12 rounded down to 10 ,
Both number are compatible now the product of these numbers are,
20 x 10 = 200
Therefore, the estimated product of 20 x 10 is 200 and actual product is 264 then it is under estimate,
The correct answer is 200(under estimate) (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. If the product of estimate is less than actual product then it is under estimate other wise it is over estimate. Apply same methods in similar questions.
