Question

Trying to understand the estimate sum of 87+34 I know the answer is 121 and we rounded to 120 but how do I round the 87 and 34

I put 87=90 and 34=30 which will make 120 still but I thought anything higher than 5 will round up and anything under 5 rounds down

Answer 1

That's right, when you round 87+34, you'll get 90+30, which is 120. That's the estimated sum.