3.03 Estimation first
Lesson
Are you ready?
Do you remember how to estimate the answer to an addition problem?
Choose the right answer.
$143+33$143+33 will be in the:
$100$100s
A$200$200s
B
Learn
Let's see how we can estimate the answer to a subtraction problem, by rounding our numbers first.
Apply
Choose the right answer.
$38-6$38−6 will be in the:
$30$30s
A$20$20s
B
Remember!
When we need to solve a subtraction problem, we can still round our numbers to the nearest $10$10 or $100$100, just as we would for addition. We don't need the exact answer so this gives us an idea of what our answer should be close to.