41
Expressions
Textbook Part 1, pp. 84–85
GoalUnderstand a numerical expression and its value; turn words into maths.
New words
numerical expression · sonli ifodavalue of an expression · ifodaning qiymatithe sum of · yig‘indisithe difference of · ayirmasi
Explanation
A record made of numbers and operation signs is a numerical expression: 5 + 3, 9 − 4. The result of working it out is the value of the expression. “The sum of five and three is eight” → 5 + 3 = 8. “The difference of five and three is two” → 5 − 3 = 2.
Worked examples
2 pupils from class 1A and 5 from 1B ran in a race. Certificates given: 2 + 5 = 7.
“The sum of three and seven is ten” → 3 + 7 = 10 ✓.
Class activity
The teacher reads a phrase (“the difference of nine and four”); children write the expression on a mini whiteboard and find its value.
Practice
1
Write in maths: the sum of six and two.
6 + 2 = 8
2
Write in maths: the difference of ten and nine.
10 − 9 = 1
3
True or false? “The difference of eight and six is three.”
False: 8 − 6 = 2
4
On the first day of a kurash championship the team won 2 gold, 1 silver and 3 bronze medals. How many in all?
6