Subtract multiples of 10

key notes :

Understanding Multiples of 10:

  • Introduce numbers like 10, 20, 30, 40, up to 100 as multiples of 10.
  • Explain that these numbers end in zero.

Visual Representation:

  • Use number lines to show subtraction steps.
  • Illustrate with base-ten blocks or ten-frames to visually demonstrate groups of tens being taken away.

Simple Subtraction Concepts:

  • Begin with simple examples like 30 – 10 or 50 – 20.
  • Emphasize that only the tens place changes during subtraction, while the ones place remains zero.

Relate to Everyday Situations:

  • Use real-life examples, such as subtracting sets of 10 apples or toys to make the concept relatable.

Mental Math Strategies:

  • Encourage students to count backward by tens.
  • Practice mental math by visualizing tens as groups being removed.

Learn with an example

🥤 Subtract: 40 – 30 =

Notice that both numbers have 1 zero at the end. When the number of zeros is the same, it is easy to subtract. First, arrange the numbers one above the other:

40 – 30=____

Next, subtract the zeros. Wherever there is a zero below another zero, place a zero at the bottom. This is because zero minus zero equals zero.

40 – 30=0

Now subtract the remaining digits. Four minus three is one.

40 – 30=10

🥤 Subtract: 60 – 30 =

Notice that both numbers have 1 zero at the end. When the number of zeros is the same, it is easy to subtract. First, arrange the numbers one above the other:

60 – 30

Next, subtract the zeros. Wherever there is a zero below another zero, place a zero at the bottom. This is because zero minus zero equals zero.

60 – 30=0

Now subtract the remaining digits. Six minus three is three.

60 – 30=30

🥤 Subtract: 80 – 40 =

Notice that both numbers have 1 zero at the end. When the number of zeros is the same, it is easy to subtract. First, arrange the numbers one above the other:

80 – 40

Next, subtract the zeros. Wherever there is a zero below another zero, place a zero at the bottom. This is because zero minus zero equals zero.

80 – 40=0

Now subtract the remaining digits. Eight minus four is four.

80 – 40=40

Let’s practice!