Working efficiently means finding a way to solve a problem quickly whilst also maintaining accuracy.

Pupils use strategies to make solving calculations more efficient

Maths

In this 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 future unit pupils will use their knowledge to calculate with decimal numbers using column addition and subtraction.

In the prior unit pupils revisited column addition with regrouping and column subtraction with exchanging to solve problems. They read Roman numerals to 100. In this 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.

Column addition and subtraction with 4-digit numbers

Which equations could be more easily solved using a mental calculation? 

Which equations would it be most efficient to solve using column subtraction? 

Subtract 1 from each number then find the difference

Add 1 to each number then find the difference

What is the most efficient way to calculate 1,745 − 199 = ? 

Complete the column addition. What number has been added to 3,065 to sum to 8,347? {{ }}

Complete the column subtraction. What is the missing whole? {{ }}

Which equations would it be most efficient to solve using column subtraction?

Alex is trying to calculate the sum of 214 and 497     Which hundreds number will be closest to his answer? 

What is the most efficient way to calculate 285 − 99 = ? 

The hundreds digit of the sum is incorrect.

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

The ones digit of the difference is incorrect.

The tens digit of the difference is incorrect.

The hundreds digit of the difference is incorrect.

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

This lesson will soon be taken down.

Pupils use strategies to make solving calculations more efficient

Lesson outcome