We want to show that 10 more than 59 is 69. How many more 10 rods should we add to the picture?
10 more than 59 is 69. We already know that 10 more than 59 is 69. We just have to add some 10 rods to make sure that the picture shows this. How many tens rods does our picture have at the moment? One, two, three, four, five. The pictures shows five 10s. Five 10s are worth 50, 10, 20, 30, 40, 50. And we know there are nine ones. The number of ones doesn’t change in this sum because we’re just adding 10.
So, at the moment, the tens rods and the ones blocks make the number 59. 10 more than 59 would give us six 10s. Because we already know that 10 more than 59 is 69. To show 69, we would need 6 10 rods. We would have to add one more tens rod to make the number 69. Six 10s are 60, plus the nine ones makes the number 69. So, if we want to show 10 more than 59 is 69, we would need to add one more tens rod to the picture.