Using bar models to represent addition and subtraction word problems

Maths

Measures

We know Ant had 78 marbles and then had 128 marbles. We don't know how many marbles Addy gave him. The relationship between the known and unknown values are that you have to add both known values together to get the unknown value (125 + 78)

We know Ant had 78 marbles and then had 128 marbles. We don't know how many marbles Addy gave him. The relationship between the known and unknown values are that you have to compare the difference between them (125-78)

We know Ant had 78 marbles and then had 128 marbles. We don't know how many marbles Addy gave him. The relationship between the known and unknown values are that you have to compare the difference between them (78-125)

Match the word problem with the correct bar model

What is the calculation required to solve this word problem?

Addy and Melvin collected wastewater, measuring them each month. In April they collected 1 litre and 500 ml and in May they collected another 7 litre and 500 ml. What was the weight of the cans they collected altogether?

Buttons and Addy compared how much water they drank in a day. Addy drank 7 litres and 500 ml. Buttons drank 1 litre and 500 ml less. How much water did Buttons drink?

Mr Slade treated his class to some juice for playing nicely in the hot weather. He used 1 litre and 500 ml of squash. With the right amount of water, it made 7 litres and 500 ml of juice. How much water was in the juice?

Using bar models to represent addition and subtraction word problems

Lesson outcome