Estimation means to find a value that is close enough to the right answer, usually with some thought or calculation involved.

The process of unitising and exchanging between place values is known as regrouping.

Use column addition with regrouping to solve problems

Maths

In this unit pupils will identify the addends and the sum in column addition. They will use their knowledge of place value to correctly lay out column addition. In the future unit pupils will identify the minuend and the subtrahend in column subtraction and explain the column subtraction algorithm. They will subtract from a 2-digit number using column subtraction with exchanging.

In the prior unit pupils accurately and efficiently solved multi-step addition and subtraction problems. They understood and explained how both addition and subtraction equations could be used to describe the same additive relationship. In this unit pupils will identify the addends and the sum in column addition. They will use their knowledge of place value to correctly lay out column addition.

Column addition

Estimate the answer to 287 + 109 =
Which hundreds number is closest to the answer?

Estimate the answer to each calculation. 
Which have answers close to 800? 

Which calculations will give a sum that is odd? 

Which two of these numbers have a sum of 633? 

What is the missing tens digit in the second addend in the column addition?

What is the missing ones digit in the second addend in the column addition?

What would be a good estimate for the sum of 149 + 152?

Which of these calculations would it be more efficient to calculate mentally? 

Which calculations will give a sum that is even? 

Starter Quiz