## The sum of two numbers is 35 . the smaller number is 13 less than the larger number. what are the numbers?

October 12, 2019// Blog//

Children will use the Make a Ten strategy in this lesson, along with

other strategies. Remind children that if they are adding two numbers

such as 8 + 5, they can regroup the numbers to make adding easier. Tell

children that they can take 2 from the 5 and add the 2 to 8 to make a

ten. Also remind them that they must remember to subtract the 2 from the

5, leaving a 3, so they add 10 and 3 and get 13. Tell children that

they will use this strategy to add two-digit numbers.

Materials: overhead projector, ten-frames and

counters, tens and ones workmat, bundles of 10 craft sticks and single

sticks, large number line, and large hundred chart

Preparation: Prepare a tens and ones workmat and a

ten frame for use on the overhead. Make 9 bundles of craft sticks, 10

per bundle, using rubber bands to hold them together. Or use tens and

ones blocks. Make a large number line and hundred chart for the

classroom.

Prerequisite Skills and Concepts: Children should know the addition facts to 20 and the strategies used in learning them.