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

Scaling is when a given quantity is made ___ times the size. It can be used to adjust the size of a factor. In this lesson, scaling will involve making values 10 or 100 times the size.

Multiply 1-digit numbers by decimal fractions using written methods

Maths

In this unit pupils will explain the effect of multiplying and dividing a number by 10, 100 and 1,000 and use their knowledge of multiplying decimal fractions by whole numbers to solve measures problems. In the future unit pupils will apply memorised unit conversions to convert between units of measure. They will solve measures problems involving different units including imperial units.

In the prior unit pupils calculated with decimal numbers using column addition and subtraction. In this unit pupils will explain the effect of multiplying and dividing a number by 10, 100 and 1,000 and use their knowledge of multiplying decimal fractions by whole numbers to solve measures problems.

Calculating with decimal fractions

Calculate 4.3 × 5 = {{ }} 
Use scaling to convert 4.3 into a whole number.

Which of these would be the most sensible estimate to check if this calculation is correct? 5.14 × 3 = 15.42

Lucas has 1.9 litres of water.  Sofia has three times this amount. How much water does Sofia have? {{ }} litres

Sofia has 2.46 kg of flour. Lucas has three times this amount. How much flour does Lucas have? {{ }} kg

Calculate this using short multiplication 48 × 7 = {{ }}

Calculate this using short multiplication 126 × 5 = {{ }}

Sofia has £93. Lucas has four times this amount. How much money does Lucas have? £{{ }}

Starter Quiz