First grade math 

Equal parts or equal shares

The orange circle has 2 equal parts.

The blue circle has 4 equal parts

Arrays

The first array is made of soccer balls.
The array has 2 rows and 3 columns.
2 × 3 = 6 balls
The second array is made of squares.The array has 3 rows and 4 columns.
3 × 4 = 12 squares

Quarter

Quarter = one-fourth = 1 of 4 equal parts

Associative property

Closed figure

All sides of a closed figure are connected.

Hour hand

The hour hand takes 1 hour to move from a number to the next. 

Hour or hr = 60 minutes.

Estimate

An estimate is not the same as an exact answer. We just need a number close to the exact amount. To estimate the number of marbles, we just need to know about how many

Possible answers: 15, 14, or 17

Commutative property
Whether 2 is written first or not, the answer to 2 + 1 is still 3

2-dimensional figures

Types of clocks

Cube:

A cube has 6 faces, 12 edges and 8 vertices. The cube on the right shows 3 faces with the color red, blue, and orange.

Multiple of 10

Counting up

Start at 3 and count 2 more to reach 5.

Number

A number indicates how many or how much. A numeral is used to represent the number of objects. For example, after counting the pencils on the right, we get 4. We use the numeral 4 to represent 4 pencils.

3-dimensional shapes.

3 dimensional shapes are solid shapes that have width, length, and height.

Make 10

Minute hand

The minute hand takes 5 minutes to move from a number to the next. 

Minute = seconds.

Different

The two triangles are different, but they have the same shape.

Counting down

Start at 6 and count backward to reach 2.

Composite shape

The arrow on the right is a composite shape since it is made from 2 basic shapes ( a triangle and a rectangle)

Collecting data

Expression

An expression has no equal sign

Coins
1 penny = 1 cent
1 nickel = 5 cents
1 dime = 10 cents
1 quarter  = 25 cents

2 dimes + 1 quarter + 3 nickels = 60 cents

Equation

Equation always have an equal sign. The amount on the left side is equal to the amount on the right side.