SHS DirectorySHS MatchLesson PlansGES Promotion Past QuestionsStudent Lesson NotesBlogs

Basic 1 · Mathematics · Counting, Representation and Cardinality

Numbers Around a Given Number

In this topic you will find the number just before, just after and between other numbers. You will use a hundred chart.

By the end of these notes you should be able to:

  • Find the number just before and just after a number
  • Find a number between two numbers
  • Find numbers above and below a number on a hundred chart

What you already know

  • Counting forwards and backwards

Copy everything that has a blue line on its left into your notebook. The other parts are for reading.

Strand
Number
Sub-strand
Counting, Representation and Cardinality
Indicator
B1.1.1.1.2 – Identify numbers in different positions around a given number (0 – 100)

Introduction

Esi lives in house number 25. Her friend lives next door in house number 26. Numbers have neighbours too!

1. Before, After and Between

Number neighbours
Just beforeNumberJust after
141516
394041
676869

Just before means one less. Just after means one more.

33 is between 32 and 34.

2. The Hundred Chart

A hundred chart shows numbers 1 to 100 in rows of 10.

Hundred chart with 45 circled and its neighbours shaded
Figure 1: Numbers around 45 on a hundred chart Draw the part of the chart around 45.Illustration: Sirbus

Around a number on the chart

  • Left: one less.
  • Right: one more.
  • Above: ten less.
  • Below: ten more.

Example

Find the numbers around 45.

  1. Left of 45 is 44.
  2. Right of 45 is 46.
  3. Above 45 is 35.
  4. Below 45 is 55.

Answer: 44, 46, 35 and 55.

Remember: Going down one row on the chart adds 10.

New words

before
Comes just ahead of a number; one less.
after
Comes just behind a number; one more.
between
In the middle of two numbers.
hundred chart
A chart of the numbers 1 to 100 in rows of 10.

Summary

  • Just before is one less. Just after is one more.
  • On a hundred chart, the number below is ten more.
  • The number above is ten less.

Class activity: Find My Neighbours

  1. Your teacher gives your group a hundred chart and number cards.
  2. Pick a number card.
  3. Put bottle tops on its four neighbours on the chart.
  4. Say the neighbours out loud.

You need: Locally made hundred chart, Locally made number cards, Bottle tops

Exercises

Answer in your exercise book first, then check your answers.

  1. 1. What number comes just after 59?

    • A. 58
    • B. 60
    • C. 61
    • D. 69
    Show answer
    Answer: 60One more than 59 is 60.

  2. 2. On a hundred chart, which number is below 23?

    • A. 22
    • B. 24
    • C. 13
    • D. 33
    Show answer
    Answer: 33The number below is ten more.

  3. 3. 18 is between 17 and 19.

    • A. True
    • B. False
    Show answer
    Answer: True17, 18, 19 are in order.

  4. 4. The number just before 30 is 31.

    • A. True
    • B. False
    Show answer
    Answer: FalseThe number just before 30 is 29.

  5. 5. 71, ______, 73

    Show answer
    Answer: 7272 is between 71 and 73.

  6. 6. Write the numbers just before and just after 50.

    Show answer
    Answer: 49 and 5149 is one less and 51 is one more.

Homework

  1. Write the house numbers just before and after your house number (or any number your parent gives you).