Being efficient means finding a way to solve a problem quickly whilst also maintaining accuracy.

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.

Review using known facts and strategies to accurately and efficiently use and check column addition

Maths

In this unit pupils will revisit column addition with regrouping and column subtraction with exchanging to solve problems. They will read Roman numerals to 100. In the future unit pupils will consolidate column addition with regrouping and column subtraction with exchanging to solve problems. They will use known facts and strategies to accurately and efficiently calculate and check.

In the prior unit pupils identified the minuend and the subtrahend in column subtraction and explained the column subtraction algorithm. They subtracted from a 2-digit number using column subtraction with exchanging. In this unit pupils will revisit column addition with regrouping and column subtraction with exchanging to solve problems. They will read Roman numerals to 100.

Review of column addition and subtraction

Which equations will have a sum that is even?  

Which two statements are correct for the column addition shown?

Which equations could be efficiently answered using a mental calculation? 

Which calculation is the best one to estimate the sum of 154 + 247? 

Alex is trying to calculate the sum of 417 and 296    Which hundreds number will be closest to his answer? 

Look carefully at Alex’s column addition. Which of these statements about the sum is true?

Where will regrouping be needed in this column addition?

Jun has started this column addition. Complete it to find the sum.

Look at this calculation. Which two numbers add to equal the sum?  

This lesson will soon be taken down.

Review using known facts and strategies to accurately and efficiently use and check column addition

Lesson outcome