1.6 Counting in tens

Mathematics

Meet bonny and tommy

Educator section

Memorandum

Count in tens regularly, forwards and backwards, from any number.

E.g. 4 14 24 34 44 54 64 74 84 94

97 87 77 67 57 47 37 27 17 7

The learners should be aware of how important the number 10 is in our number system (decimal system).

They should know the combinations of 10 very well and must be tested regularly. Much practice is required.

Leaner section

Content

Activity: counting in tens [lo 1.3, lo 1.11, lo 1.8, lo 2.2, lo 1.7]

• Write down the number and number name for each letter:

A: ______________________________ ______________________________

B: ______________________________ ______________________________

C: ______________________________ ______________________________

D: ______________________________ ______________________________

E: ______________________________

______________________________

F: ______________________________

______________________________

G: ______________________________

______________________________

H: ______________________________

• Look carefully at: 1 ; 1 1 ; 21 ; 31 ; 41 ; 51 ; 61 ; 71 ; 81 ; 91

Which numbers come under 5 and 9 ?

5 : 15 ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; 95

9 ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; 99

• Count in tens. Now begin with:

3 ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; 93

• Count backwards in tens:

93 ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; _____ ; 3

Bonny and Tommy have made these “tens bugs”.

• The two circles connecting them are equal to 10.

3 + 7 = 10 7 + 3 = 10

• Fill in the missing numbers.

• Complete:

7 and 3

____ and 9

____ and 5

3 and 7

9 and ____

5 and ____

____ and 8

____ and 6

8 and ____

6 and ____

Let’s say that 10 ’s 3 breaks off, then 7 remains.

Number sentence: 10 - 3 = 7

If 10 ’s 7 breaks off, then 3 remains.

Number sentence: 10 - 7 = 3

• Think!

Always think of the two parts!

• Help Bonny and Tommy to add all the numbers on the cards as quickly as possible. Can you think of a quick way? Show what you are doing.

				Total:
Do these:

• The ripe apples are equal to 10. Only colour the ripe apples.

• Bonny says:

Complete the patterns.

• Tommy says:

Complete these patterns.

• Use your own method to solve the problem. You may draw as well.

Divide 30 smarties among Bonny and Tommy and their friend, Terry, so that they all get the same number. How many smarties will each one get?

• Each will get ___________________________________________________

Assessment

Learning Outcome 1: The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems.

Assessment Standard 1.3: We know this when the learner knows, reads and writes number symbols and names from 1 to at least 1 000;

Assessment Standard 1.7: We know this when the learner solves and explains solutions to practical problems that involve equal sharing and grouping and that lead to solutions that also include unitary and nonunitary fractions (e.g. 1¼1 , ¾4);

Assessment Standard 1.8: We know this when the learner can perform calculations, using appropriate symbols, to solve problems involving:

1.8.1 addition and subtraction of whole numbers with at least 3 digits;

1.8.2 multiplication of at least whole 2-digit by 1-digit numbers;

1.8.3 division of at least whole 2-digit by 1-digit numbers;

• estimation;

Assessment Standard 1.9: We know this when the learner performs mental calculations involving:

1.9.1 addition and subtraction for numbers to at least 50;

1.9.2 multiplication of whole numbers with solutions to at least 50;

Learning Outcome 2: The learner will be able to recognise, describe and represent patterns and relationships, as well as to solve problems using algebraic language and skills.

Assessment Standard 2.2: We know this when the learner copies and extends simple number sequences to at least 1 000.