3
Looking back at Primary 2
Discover Mathematics P2: Term 2, Lessons 111–120
GoalLook back at what we learned in Primary 2 and try problems from many topics.
New words
place value · the value of a digit by its placefraction · a part of a whole or of a grouparray · objects in equal rows
Explanation
In Primary 2 you learned many things. You read bar graphs, pictographs and number lines. You wrote numbers up to 999 and compared them. You added and subtracted with regrouping. You learned plane shapes and solids, measured in centimetres, grams and kilograms, told time to five minutes and counted money in LE. You found patterns, built arrays, estimated, and named halves, thirds and fourths. Each one is a tool. Choose the right tool for each problem.
| Topic | Example |
|---|---|
| Place value | 345 = 300 + 40 + 5 |
| Adding | 48 + 37 = 85 |
| Money | 20 LE + 10 LE = 30 LE |
| Fractions | 1/4 of 8 = 2 |
| Arrays | 4 + 4 + 4 = 12 |
| Time | Quarter past 3 is 3:15 |
Worked examples
Order 408, 480 and 84 from least to greatest. 84 has only two digits, so it is least. Then compare 408 and 480: 408 is less. The order is 84, 408, 480.
A notebook costs 20 LE and a pen costs 10 LE. Together they cost 20 + 10 = 30 LE.
There are 12 apples. 1/2 of them are red. Split 12 into 2 equal groups of 6. 1/2 of 12 = 6 red apples.
Class activity
My Primary 2 book. Make a small book from folded paper. On each page, draw or write one thing you learned this year: a shape, a graph, a money problem, a fraction, a pattern. Add one example with numbers. Share your book with someone at home.
Practice
1
Write 530 in expanded form.
500 + 30.
2
Which is greater: 405 or 450?
450 is greater, because 5 tens is more than 0 tens.
3
How many minutes are in half an hour and in a quarter of an hour?
30 minutes and 15 minutes.
4
What time does the clock show?
Half past eight, 8:30.
5
A shape has 4 sides and 4 vertices. What is it called? Name one.
A quadrilateral, for example a square or a rectangle.